Correct Answer: A

Rationale: To estimate the number of pregnant women, multiply the total population by 3.5%.

Correct Answer: B

Rationale: The sex ratio is calculated as the number of males for every 100 females in the population. To find the sex ratio, divide the number of males by the number of females and multiply by 100. In this case, (35,299,000 / 34,968,000) * 100 ≈ 100.94:100. Therefore, the correct answer is B, indicating that there were approximately 100.94 males for every 100 females in the Philippines in 1995.

Correct Answer: B

Rationale: A survey, specifically a sample survey, is the most appropriate method for gathering data about a sample of the population. In this scenario, focusing on families with members who are part of the target population for PEM requires collecting specific data from a subset of the overall population, making a survey the best choice for this purpose.

Correct Answer: B

Rationale: Under 5-year-old children are particularly susceptible to protein-energy malnutrition (PEM) because they have generally been weaned and often rely on others for food. This population may suffer from poor intrafamilial food distribution, contributing to their vulnerability.

Correct Answer: D

Rationale: Post-natal care is the care provided to a woman after childbirth, typically within the first month. It involves various aspects such as monitoring the mother's health, providing guidance on maternal nutrition, promoting breastfeeding, and educating on maternal and child care practices. This comprehensive care aims to ensure the well-being of both the mother and the newborn during the postpartum period.