The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Which of these is the best study to evaluate effect and outcome?   (A) Clinical trial   (B) Coho   (C) Case control study   (D) Cross sectional study
['(A) Clinical trial <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Clinical trial \n (B) Coho \n (C) Case control study \n (D) Cross sectional study <> possible answers', '  Which of these is the best study to evaluate effect and outcome? <> context@']