The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Which of the following is not involved in blood clotting?   (A) Calcium   (B) Prothrombin   (C) Fibrinogen   (D) Fe+2
['(D) Fe+2 <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Calcium \n (B) Prothrombin \n (C) Fibrinogen \n (D) Fe+2 <> possible answers', '  Which of the following is not involved in blood clotting? <> context@']