**Core Concept**
The Central Birth and Death Registration Act, 1969, mandates the registration of births and deaths in India to maintain accurate vital statistics. The timely registration of births is crucial for tracking demographic changes, monitoring public health trends, and providing essential services to the population.

**Why the Correct Answer is Right**
The correct answer is 21 days, as per Section 5 of the Central Birth and Death Registration Act, 1969. This timeframe allows for the collection of accurate and complete information about the birth, including the date, time, place, and details of the parents. The registration process helps to prevent fraudulent or inaccurate records and ensures that essential services, such as immunization and social security benefits, are provided to the newborn.

**Why Each Wrong Option is Incorrect**
**Option A:** 7 days - This timeframe is too short for collecting accurate information and may lead to incomplete or inaccurate registration.
**Option B:** 10 days - While this is closer to the correct answer, it still does not provide sufficient time for collecting all necessary information.
**Option C:** 14 days - Again, this is not the correct timeframe, and the registration process may be delayed or incomplete.

**Clinical Pearl / High-Yield Fact**
Remember, timely registration of births is essential for public health surveillance and providing essential services to the population. Healthcare professionals should ensure that births are registered within the specified timeframe to maintain accurate vital statistics.

**✓ Correct Answer: D. 21 days**