Urban air contains more sulfur dioxide than does rural air, and plants in cities typically grow more slowly than do plants in rural areas. In an experiment to see how much of the difference in growth is due to sulfur dioxide, classes in an urban and a rural school grew plants in greenhouse at their schools and filtered the greenhouse air to eliminate sulfur dioxide. Plants in the urban greenhouse grew more slowly than those in the rural greenhouse.Which of the following, if true, would it be most important to take into account in evaluating the result?a)The urban school was located in a part of the city in which levels of sulfur dioxide in the air were usually far lower than is typical for urban areas.b)At both schools, the plants in the greenhouses grew much more quickly than did plants planted outdoors in plots near the greenhouse.c)The urban class conducting the experiment was larger than the rural class conducting the experiment.d)Heavy vehicular traffic such as is found in cities constantly deposits grime on greenhouse windows, reducing the amount of light that reaches the plants inside.e)Because of the higher levels of sulfur dioxide in the air at the urban school, the air filters for the urban school’s greenhouse were changed more frequently than were those at the rural school.Correct answer is option 'D'. Can you explain this answer?

Question

Urban air contains more sulfur dioxide than does rural air, and plants in cities typically grow more slowly than do plants in rural areas. In an experiment to see how much of the difference in growth is due to sulfur dioxide, classes in an urban and a rural school grew plants in greenhouse at their schools and filtered the greenhouse air to eliminate sulfur dioxide. Plants in the urban greenhouse grew more slowly than those in the rural greenhouse.Which of the following, if true, would it be most important to take into account in evaluating the result?a)The urban school was located in a part of the city in which levels of sulfur dioxide in the air were usually far lower than is typical for urban areas.b)At both schools, the plants in the greenhouses grew much more quickly than did plants planted outdoors in plots near the greenhouse.c)The urban class conducting the experiment was larger than the rural class conducting the experiment.d)Heavy vehicular traffic such as is found in cities constantly deposits grime on greenhouse windows, reducing the amount of light that reaches the plants inside.e)Because of the higher levels of sulfur dioxide in the air at the urban school, the air filters for the urban school&rsquo;s greenhouse were changed more frequently than were those at the rural school.Correct answer is option 'D'. Can you explain this answer?

Answer

To evaluate the result, we need to identify the factor that could potentially explain why the plants in the urban greenhouse grew more slowly than those in the rural greenhouse, despite the elimination of sulfur dioxide.

Let's examine each answer choice:

(A) The urban school was located in a part of the city in which levels of sulfur dioxide in the air were usually far lower than is typical for urban areas.

This answer choice suggests that the urban school's location had lower levels of sulfur dioxide compared to typical urban areas. However, the experiment has already eliminated sulfur dioxide from the greenhouse air. Therefore, this factor is not relevant to explaining the slower growth of plants in the urban greenhouse.

(B) At both schools, the plants in the greenhouses grew much more quickly than did plants planted outdoors in plots near the greenhouse.

This answer choice compares the growth of greenhouse plants with plants grown outside near the greenhouse. However, it does not provide any information about the difference in growth between the urban and rural greenhouses. Therefore, this answer choice does not help us evaluate the result.

(C) The urban class conducting the experiment was larger than the rural class conducting the experiment.

The size of the classes conducting the experiment is unrelated to the growth of plants in the greenhouses. This information does not explain why the plants in the urban greenhouse grew more slowly. Therefore, this answer choice is not relevant to evaluating the result.

(D) Heavy vehicular traffic such as is found in cities constantly deposits grime on greenhouse windows, reducing the amount of light that reaches the plants inside.

This answer choice introduces a new factor that could explain the slower growth of plants in the urban greenhouse. The grime deposited on the greenhouse windows due to heavy vehicular traffic reduces the amount of light reaching the plants, which can significantly affect their growth. This factor is relevant to evaluating the result and provides a plausible explanation for the slower growth of plants in the urban greenhouse, even after eliminating sulfur dioxide.

(E) Because of the higher levels of sulfur dioxide in the air at the urban school, the air filters for the urban school's greenhouse were changed more frequently than those at the rural school.

This answer choice provides information about the frequency of air filter changes in the urban and rural greenhouses. While it indirectly relates to sulfur dioxide levels, it does not explain why the plants in the urban greenhouse grew more slowly. Therefore, this answer choice is not as important for evaluating the result compared to answer choice (D).

In conclusion, the most important factor to consider in evaluating the result is answer choice (D), which highlights the impact of grime deposition on greenhouse windows due to heavy vehicular traffic, leading to reduced light reaching the plants. This factor provides a plausible explanation for the slower growth of plants in the urban greenhouse, even after eliminating sulfur dioxide.

Answer