Which of the following is NOT a measure of population control?

The correct answer is Option (4) → Imbalanced sex ratio

Option (1) Free availability of contraceptives — A measure (Incorrect). When contraceptives cost nothing, couples who want fewer children are no longer held back by the price, so they can space or prevent births. Fewer births slow the growth of population, which makes it one of the measures which can help population control.

Option (2) Tax disincentives for large families — A measure (Incorrect). A higher tax on large families makes every extra child costlier for the parents. This gives couples a money reason to keep the family small, and so it limits births.

Option (3) Increased time interval between kids — A measure (Incorrect). Family planning is the spacing or preventing the birth of children. A longer gap between children means fewer births over the years a woman can bear children, and also better health for her, so population grows more slowly.

Option (4) Imbalanced sex ratio — Not a measure (Correct). An imbalanced sex ratio means the numbers of females and males in a population are unequal. It is a condition of the population, often a problem in itself, and not a step taken to limit births.