Which among the following constitutes preventive checks:
A. postponement of marriage
B. Celibacy

Both A and B

As per Malthus, Preventive checks are voluntary measures that individuals or societies take to limit population growth. In the context of the given options:

• A. Postponement of marriage is a form of preventive check as it delays the start of childbearing, thereby reducing the number of births.
• B. Celibacy is also a preventive check as it involves abstaining from marriage and sexual activity, leading to the prevention of childbirth
• Therefore, both A and B are examples of preventive checks, and the correct option is "Both A and B."