<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 29-year-old woman comes to the office with her husband because she has had 4 spontaneous abortions. Regarding her medical history, she was diagnosed with systemic lupus erythematosus 9 years ago, had a stroke 3 years ago, and was diagnosed with deep vein thrombosis in the same year. She has no relevant family history. Her vital signs include: heart rate 78min, respiratory rate 14min, temperature 37.5C 99.5F, and blood pressure 12085 mm Hg. The physical examination is unremarkable. The complete blood count results are as follows:Hemoglobin 12.9 gdLHematocrit 40Leukocyte count 8,500mm3Neutrophils 55Bands 2Eosinophils 1Basophils 0Lymphocytes 29Monocytes 2Platelet count 422,000mm3His coagulation test results are as follows:Partial thromboplastin time activated 50.9 sProthrombin time 13.0 sA VDRL test is done, and the result is positive. Mixing studies are performed, and they fail to correct aPTT. What is the most likely cause in this patient?? A: Protein C deficiency, B: Protein S deficiency, C: Antiphospholipid syndrome, D: Mutation of Leiden V factor, E: Antithrombin deficiency,  <response>: Based on the information provided in the question stem, this patient has a history of multiple spontaneous abortions, systemic lupus erythematosus, stroke, deep vein thrombosis, and a positive VDRL test. The prolonged aPTT that fails to correct on mixing studies indicates a coagulation factor deficiency or inhibitor. Given her history of thrombotic events rather than bleeding, a hypercoagulable state is most likely. The antiphospholipid syndrome can be associated with systemic lupus erythematosus and causes both arterial and venous thromboses as well as pregnancy complications like recurrent miscarriages. Therefore, antiphospholipid syndrome is the most likely diagnosis. Protein C, protein S, and antithrombin deficiencies typically cause bleeding rather than clotting. The factor V Leiden mutation also causes hypercoagulability but is not associated with pregnancy loss or positive VDRL.C: Antiphospholipid syndrome 