<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 70-year-old male comes to the emergency department complaining of severe back pain. The pain started 20 minutes ago when he was sitting and watching TV. He describes the pain as intense, epigastric, and radiating to his back. His vitals on presentation to the emergency department are blood pressure is 15075 mmHg, pulse is 110min, and respirations are 24min with an oxygen saturation of 98 on room air. His body mass index is 35 kgm2 and he appears pale and in visible pain. On abdominal exam, his abdomen is tender and a pulsatile mass is felt in the midline during deep palpation. His past medical history includes diabetes, hypertension well-controlled on medications, and a history of benign prostatic hyperplasia. His social history is notable for consuming 2-3 beers per night and a smoking history of 12 pack per day. Which of the following is considered the greastest risk factor for this patients condition?? A: Obesity, B: Smoking, C: Diabetes, D: Alcohol consumption, E: Benign prostatic hyperplasia,  <response>: This is a clinical vignette describing a 70-year-old male presenting with sudden onset severe epigastric and back pain. Key findings include hypertension, obesity, smoking history, alcohol use, and a pulsatile abdominal mass on exam. This presentation is most consistent with an abdominal aortic aneurysm AAA. The greatest risk factor for AAA is smoking, as it causes damage and weakening of the aortic wall. Obesity and hypertension are also risk factors, but smoking has the strongest association. Diabetes and benign prostatic hyperplasia are unrelated to AAA risk.B: Smoking 