The following are multiple choice questions (with answers) about medical knowledge.   **Question:** A girl comes with symptoms of involuntary movements. Sydenham's chorea and acute rheumatic fever is suspected. Other major criteria of rheumatic fever (ahritis, skin rashes, subcutaneous nodules and carditis) were absent. No evidence of sore throat. Best investigation to prove rheumatic etiology is:   (A) Antistreptolysin S   (B) Antistreptolysin O   (C) Throat culture   (D) PCR for M protein
['(B) Antistreptolysin O <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Antistreptolysin S \n (B) Antistreptolysin O \n (C) Throat culture \n (D) PCR for M protein <> possible answers', "  A girl comes with symptoms of involuntary movements. Sydenham's chorea and acute rheumatic fever is suspected. Other major criteria of rheumatic fever (ahritis, skin rashes, subcutaneous nodules and carditis) were absent. No evidence of sore throat. Best investigation to prove rheumatic etiology is: <> context@"]