Which type of study design is best suited for studying the prevalence of a disease?

Correct Answer: C

Rationale: Cross-sectional studies (C) measure prevalence at a point in time (e.g., hypertension rates). A and B focus on associations, D on interventions.

Correct Answer: B

Rationale: Case-control studies (B) efficiently study rare diseases (e.g., cancer) by starting with cases. A, C, and D are false.

Correct Answer: C

Rationale: Cohort studies (C) compare exposed vs. unexposed outcomes (e.g., smoking and cancer). A is snapshot, B is retrospective, D is experimental.

Correct Answer: C

Rationale: Matching (C) controls confounders (e.g., age) in case-control studies. A, B, and D are incorrect or unrelated.

Correct Answer: B

Rationale: Justice (B) ensures fair burden-benefit distribution (e.g., no group exploited). A is beneficence, C is autonomy, D is non-maleficence.