The correct answer is option 'b) 7 years'.

**Explanation:**

Literacy rate is a measure of the percentage of people in a population who can read and write. It is commonly used as an indicator of a country's education level and overall development. The literacy rate is usually calculated by dividing the number of literate individuals by the total population and multiplying by 100 to get the percentage.

In this question, the literacy rate is denoted for a specific age group. The options given represent different age groups, and we need to determine which one is correct for calculating the literacy rate.

To understand why option 'b) 7 years' is the correct answer, let's analyze the other options:

a) 5 years: Calculating the literacy rate for the population above 5 years of age would include young children who are typically not yet enrolled in primary education. This age group may not be suitable for measuring literacy as many children are still in the early stages of learning to read and write.

c) 11 years: This age group includes children who are usually enrolled in primary education. However, some children may still be in the early stages of literacy development, while others may have already acquired basic reading and writing skills. This age group is a possible option for calculating literacy rate, but it may not provide a comprehensive picture of a country's literacy level.

d) 16 years: This age group includes adolescents who have completed or are about to complete their secondary education. By this age, individuals are expected to have acquired basic literacy skills. However, using this age group may not capture the literacy levels of the entire population, as it excludes individuals who have not had the opportunity to receive formal education or who have dropped out before completing secondary education.

Therefore, option 'b) 7 years' is the most suitable choice for calculating the literacy rate as it includes children who have typically started primary education and have had some exposure to reading and writing instruction. This age group provides a more representative measure of the overall literacy level within a population.