<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 24-year-old woman comes to the physician because of pain and swelling of her left leg over the past 24 hours. The pain is worse while walking and improves when resting. Seven months ago, she was diagnosed with a pulmonary embolism and was started on warfarin. Anticoagulant therapy was discontinued 1 month ago. Her sister has systemic lupus erythematosus. The patient does not smoke. She currently takes no medications. Her temperature is 37.8C 100F, pulse is 78min, and blood pressure is 12372 mm Hg. On physical examination, the left calf is diffusely erythematous, swollen, and tender. Dorsal flexion of the left foot elicits pain. Cardiopulmonary examination shows no abnormalities. On duplex ultrasonography, the left popliteal vein is not compressible. Laboratory studies show an elevated serum concentration of D-dimer and insensitivity to activated protein C. Further examination is most likely to show which of the following?? A: Antiphospholipid antibodies, B: Mutation of coagulation factor V, C: Mutation of prothrombin, D: Elevated levels of homocysteine, E: Deficiency of protein C,  <response>: This is a question about deep vein thrombosis DVT. The patient is a 24-year-old woman with left leg pain and swelling that started suddenly 24 hours ago. She has a history of pulmonary embolism 7 months ago and was on warfarin until 1 month ago. Her sister has systemic lupus erythematosus. On exam, she has left calf erythema, swelling, and tenderness, as well as pain with dorsiflexion of the foot. Duplex ultrasound shows noncompressible left popliteal vein, confirming DVT. Lab tests show elevated D-dimer and activated protein C resistance. The key finding here is activated protein C resistance, which indicates a mutation in factor V Leiden. This mutation leads to increased risk of venous thromboembolism. Of the answer choices, mutation of coagulation factor V choice B is most consistent with the clinical presentation and test results.B: Mutation of coagulation factor V 