This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
[{'content': 'Which of the following is NOT a risk factor for pulmonary embolism? \nSelect and explain. \nA. Protein S deficiency, B. Malignancy, C. Obesity, D. Progesterone therapy', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Risk factors for pulmonary embolism are thrombophilias like factor V leiden mutation, protein C, S deficiency, APLA syndrome. Other common predisposing factors include cancer, systemic aerial hypeension, chronic obstructive pulmonary disease, long-haul air travel, air pollution, obesity, cigarette smoking, eating large amounts of red meat, oral contraceptives, pregnancy, postmenopausal hormone replacement, surgery, and trauma. Progesterone therapy is not specifically mentioned as a cause of pulmonary embolism. Ref: Harrisons principles of internal medicine, 18th edition, Page: 2170.', 'role': 'assistant'}]