<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 74-year-old man presents to the emergency department with sudden-onset abdominal pain that is most painful around the umbilicus. The pain began 16 hours ago and has no association with meals. He has not been vomiting, but he has had several episodes of bloody loose bowel movements. He was hospitalized 1 week ago for an acute myocardial infarction. He has had diabetes mellitus for 35 years and hypertension for 20 years. He has smoked 1520 cigarettes per day for the past 40 years. His temperature is 36.9C 98.42F, blood pressure is 9565 mm Hg, and pulse is 95min. On physical examination, the patient is in severe pain, there is mild periumbilical tenderness, and a bruit is heard over the epigastric area. Which of the following is the definitive test to assess the patient condition?? A: Mesenteric angiography, B: CT scanning, C: Plain abdominal X-rays, D: Colonoscopy, E: Complete blood count,  <response>: This is a clinical vignette describing a 74-year-old man with sudden-onset abdominal pain around the umbilicus, bloody diarrhea, recent myocardial infarction, longstanding diabetes and hypertension, smoking history, mild epigastric tenderness, and an epigastric bruit on exam. The key findings are the acute abdominal pain associated with bloody diarrhea in a patient with cardiovascular risk factors, which raises suspicion for acute mesenteric ischemia. The epigastric bruit further increases this suspicion. Mesenteric angiography allows direct visualization of the mesenteric vessels and detection of any occlusion causing ischemia. CT scanning may show secondary signs of ischemia but cannot directly visualize the vessels. Plain films, CBC, and colonoscopy are not useful for diagnosing acute mesenteric ischemia.Therefore, mesenteric angiography is the definitive test to diagnose acute mesenteric ischemia in this patient.A: Mesenteric angiography 