The following are multiple choice questions (with answers) about medical knowledge.   **Question:** A 14-year-old boy is brought to the emergency department by his mother after falling from the jungle gym and developing severe left knee pain and swelling. On presentation, he is found to be in pain with a hot, swollen, erythematous left knee. His past medical history is significant for abnormal coagulation lab tests before an appendectomy, but his mother cannot recall the exact details. Coagulation tests are conducted with the following results:  Bleeding time: 3 minutes Prothrombin time: 11 seconds Partial thromboplastin time: 53 seconds Bradykinin formation: decreased  Which of the following factors is most likely defective in this patient?   (A) Factor VII   (B) Factor VIII   (C) Factor IX   (D) Factor XII
['(D) Factor XII <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Factor VII \n (B) Factor VIII \n (C) Factor IX \n (D) Factor XII <> possible answers', '  A 14-year-old boy is brought to the emergency department by his mother after falling from the jungle gym and developing severe left knee pain and swelling. On presentation, he is found to be in pain with a hot, swollen, erythematous left knee. His past medical history is significant for abnormal coagulation lab tests before an appendectomy, but his mother cannot recall the exact details. Coagulation tests are conducted with the following results:\n\nBleeding time: 3 minutes\nProthrombin time: 11 seconds\nPartial thromboplastin time: 53 seconds\nBradykinin formation: decreased\n\nWhich of the following factors is most likely defective in this patient? <> context@']