You are answering a USMLE-style medical question. Question: A 17-year-old female is brought to the emergency room by her father because she has been experiencing shortness of breath and chest pain. She says that the chest pain is worse when she breathes or coughs. Furthermore, on the way to the hospital she noticed that there were specks of blood on a tissue that she coughed into. She has no previous medical history and does not recall anything that could have provoked these symptoms. On presentation her temperature is 99°F (37.2°C), blood pressure is 107/65 mmHg, pulse is 102/min, respirations are 21/min, and O2 saturation is 91% on room air. Further testing shows a large filling defect in the pulmonary vessels, and the patient is started on an appropriate treatment intravenously. After drug administration, the effects of the drug are monitored using a standard blood test. Surprisingly, the test results come back within normal parameters. The most likely underlying cause of this patient's symptoms has which of the following modes of inheritance? Options: A) Autosomal dominant B) Autosomal partial dominance C) X-linked dominant D) X-linked recessive Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.