<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 62-year-old man is brought to the emergency department with a sudden onset of severe chest pain, that he describes as tearing. The pain started 90 minutes back and is now referring to the upper back. There is a history of essential hypertension for the past 17 years. The patient has smoked 2030 cigarettes daily for the past 27 years. Vital signs reveal: temperature 36.8C 98.2F, heart rate 105min, and blood pressure 19291 mm Hg in the right arm and 15981 mm Hg in the left arm. Pulses are absent in the right leg and diminished in the left. ECG shows sinus tachycardia, and chest X-ray shows a widened mediastinum. Transthoracic echocardiography shows an intimal flap arising from the ascending aorta and extended to the left subclavian artery. Intravenous morphine sulfate is started. Which of the following is the best next step in the management of this patient condition?? A: Intravenous metoprolol, B: Intravenous hydralazine, C: Oral aspirin, D: Chest magnetic resonance imaging, E: D-dimer,  <response>: This is a patient with acute chest pain and signs of aortic dissection on physical exam, ECG, chest X-ray and echocardiography. The key findings are sudden onset severe tearing chest pain radiating to the back, asymmetric blood pressures and absent pulses in the right leg, widened mediastinum on X-ray, and echocardiographic evidence of aortic dissection. The goal is to urgently lower blood pressure to decrease shear forces on the aortic wall and prevent further dissection. Metoprolol is a beta blocker that can lower blood pressure and heart rate. Hydralazine also lowers blood pressure but less predictably. Aspirin and MRI are not urgent next steps. D-dimer is not useful for diagnosing aortic dissection when there is already strong clinical evidence.A: Intravenous metoprolol 