Answer:

To answer this question, we need to understand the given options and determine the correct answer based on the information provided. Let's analyze each option and find the correct one.

Option A: 15 1971
Option B: 15 1972
Option C: 15 1973
Option D: 15 1974

Based on the given options, we can see that the number '15' is common in all the options. The only difference lies in the year mentioned after '15'.

Now, let's think logically and try to find the correct answer.

Since this question belongs to the Class 5 category, it is reasonable to assume that the number '15' represents a specific event or occurrence. It could possibly be the age of a person, the number of years since a particular event, or any other significant factor related to the given year.

Considering this, we can conclude that the number '15' refers to the age of someone in the specified year. Therefore, we need to determine which year corresponds to a person being 15 years old.

Let's do some calculations:

If we subtract 15 from 1971, we get 1956. Therefore, in 1971, the person would have been 15 years old in 1956.

If we subtract 15 from 1972, we get 1957. Therefore, in 1972, the person would have been 15 years old in 1957.

If we subtract 15 from 1973, we get 1958. Therefore, in 1973, the person would have been 15 years old in 1958.

If we subtract 15 from 1974, we get 1959. Therefore, in 1974, the person would have been 15 years old in 1959.

Based on these calculations, we can see that the correct answer is Option B: 15 1972. In 1972, the person would have been 15 years old in 1957.

Therefore, the correct answer to this question is Option B: 15 1972.