You are answering a USMLE-style medical question. Question: A 29-year-old woman presents to her primary care doctor for a prenatal visit. She has just learned that she is pregnant and estimates she is approximately 6 weeks pregnant given the timing of her last menstrual cycle. She has a history of recurrent fetal loss. In total, she has had 4 miscarriages between the gestational ages of 8 and 15 weeks. She has a history of systemic lupus erythematosus and has had several DVTs in the past and a clot in her lung once. Her vitals today are unremarkable. She is asking if there are any treatments she should receive to prevent fetal loss. Which of the following is the most appropriate management of this patient? Options: A) Aspirin and heparin B) Aspirin and warfarin C) No treatment indicated D) Rivaroxaban Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.