What is the term for the time period when an infected person can transmit the disease to others?

Correct Answer: C

Rationale: Infectious period (C) is when transmission occurs (e.g., flu). A is exposure to symptoms, B is pre-infectious latency, D is post-infectious.

Correct Answer: C

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

Correct Answer: B

Rationale: Analytical studies (B) test hypotheses (e.g., does smoking cause cancer?). A is descriptive, C is hypothesis generation, D is clinical.

Correct Answer: B

Rationale: Cohort studies (B) select based on exposure (e.g., smokers vs. non-smokers). A is case-control, C and D are variables, not criteria.

Correct Answer: C

Rationale: Case-control studies (C) risk recall bias from retrospective data (e.g., memory errors). A, B, and D are less primary.