The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Most common single cause of pyrexia of unknown origin   (A) Mycobacterium tuberculosis   (B) Salmonella paratyphi   (C) Brucella   (D) Salmonella typhi
['(A) Mycobacterium tuberculosis <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Mycobacterium tuberculosis \n (B) Salmonella paratyphi \n (C) Brucella \n (D) Salmonella typhi <> possible answers', '  Most common single cause of pyrexia of unknown origin <> context@']