Correct Answer: B

Rationale: EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), both omega-3 fatty acids, are known to reduce the risk of cardiovascular disease.

Correct Answer: C

Rationale: Increasing potassium intake can help reduce blood pressure in hypertensive patients.

Correct Answer: B

Rationale: Immediately after a myocardial infarction, the primary concern is to allow the heart to rest and heal to prevent further damage. This is why choice B is the correct answer. While choices A, C, and D might be a part of the long-term management plan following a myocardial infarction, they are not the immediate priority. Reducing cholesterol and saturated fat intake, as well as adjusting eating habits can help prevent future heart issues, but do not directly contribute to the immediate recovery post-myocardial infarction.

Correct Answer: C

Rationale: Adolescence is the most critical stage for building bone mass, which plays a significant role in preventing osteoporosis in later life. During adolescence, approximately 45% of adult bone mass is formed. Although bone mass can be built during infancy, early childhood, and young adulthood, it is not as significant as during adolescence, making choices A, B, and D incorrect. Therefore, focusing on adequate nutrition and physical activity during adolescence is vital for long-term bone health.

Correct Answer: B

Rationale: The first step in the scientific method is to make an observation and ask a question. This is because the scientific method is a systematic process of investigation that begins with observing a phenomenon or asking a question about it. This is followed by formulating a hypothesis (Choice C), designing and conducting an experiment to test the hypothesis (Choice A), and analyzing the results to reach a consensus or conclusion (Choice D). Therefore, choices A, C, and D are incorrect as they represent steps that occur after the initial observation and question.