Population Stabilisation And Birth Control

Step 1: Understand the mechanism of oral contraceptive pills.
Oral contraceptive pills primarily function by releasing hormones (such as estrogen and progestin) that prevent the release of an egg from the ovaries. This is known as preventing ovulation.

Step 2: Analyze the options.
Oral contraceptive pills do not kill sperms or ova directly. They do not form a physical barrier between the sperm and egg; that’s the function of barrier methods like condoms. The key mechanism is preventing ovulation, so that no egg is available for fertilization.

Step 3: Conclusion.
Oral contraceptive pills prevent ovulation, making option (C) the correct answer.

Conclusion: The correct answer is (C) preventing ovulation.