Correct Answer: A

Rationale: The correct interval between doses of tetanus toxoid for pregnant women is 4 weeks. This interval ensures that pregnant women receive adequate protection against tetanus, particularly in areas where the disease is prevalent. The 4-week interval helps in building and maintaining immunity to protect both the pregnant woman and her developing baby from tetanus infection.

Correct Answer: D

Rationale: Success in utilizing the primary health care approach is indicated by the sustainability of health programs based on the community's development level. This ensures that essential health services can be maintained at all stages of community development, reflecting the core principles of primary health care.

Correct Answer: D

Rationale: To estimate the number of 1-4 year old children in a population, you can multiply the total population by the percentage of children in that age group. In this case, using the Philippine population composition as reference, which is about 11.5% for 1-4 year olds, the calculation would be 20,000 x 0.115 = 2,300 children.

Correct Answer: C

Rationale: The vastus lateralis muscle is the preferred site for intramuscular injections in infants due to its larger muscle mass and fewer major nerves and blood vessels, reducing the risk of injury or adverse effects.

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.