input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Major mechanism of action of nitrates in acute attack of angina is:-   (A) Coronary vasodilation   (B) Decreases in preload   (C) Decreases in afterload   (D) Decreases in hea rate
output: ['(B) Decreases in preload <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Coronary vasodilation  (B) Decreases in preload  (C) Decreases in afterload  (D) Decreases in hea rate <> possible answers', '  Major mechanism of action of nitrates in acute attack of angina is:- <> context']