Assertion:. It is necessary to understand the ratio between the numbers of people to the size of land. This ratio is the density of population. Reasoning: Each unit of land has limited capacity to support people living on it. .

Both Assertion (A) and reasoning (R) are correct and R is the correct explanation of A. Both Assertion (A) and reasoning (R) are correct and but R is not the correct explanation of A. Assertion (A) is true but Reasoning (R) is not correct. Assertion (A) is not true but Reasoning (R) is correct.

Both Assertion (A) and reasoning (R) are correct and R is the correct explanation of A.

Each unit of land has limited capacity to support people living on it. Hence, it is necessary to understand the ratio between the numbers of people to the size of land. This ratio is the density of population. It is usually measured in persons per sq km.