Which of the following is a method to control for confounding in the design phase of a study?

Correct Answer: C

Rationale: Matching (C) controls confounding in design (e.g., sex-matching). A is analysis, B is broad, D includes analysis methods.

Correct Answer: B

Rationale: Diagnostic tests (B) confirm or rule out disease (e.g., biopsy for cancer). A, C, and D are unrelated.

Correct Answer: C

Rationale: Tertiary prevention (C) includes rehab post-disease (e.g., stroke therapy). A is primary, B is secondary.

Correct Answer: B

Rationale: Risk factor (B) increases disease likelihood (e.g., smoking). A is protective, C is treatment, D is measure.

Correct Answer: C

Rationale: Incidence is decreasing in the West (e.g., due to fiber intake). A is false (males slightly higher). B is wrong (peak is teens). D is false (mortality down). E is off (rarer, ~1/1,500 in pregnancy).