You are answering a USMLE-style medical question. Question: A 56-year-old man recently diagnosed with cirrhosis secondary to alcohol use presents to the clinic for a follow up evaluation. He states that he has abstained from alcohol and attends a support group regularly. He has not taken any new medications or encountered any sick contacts. The patient's blood pressure is 110/70 mmHg, pulse is 65/min, and respirations are 15/min. His physical exam is grossly unremarkable. He has brought an gastroduodenoscopy report for review, which reveals that the patient has small esophageal varices with red spots. What is the next best step to prevent bleeding? Options: A) Endoscopic sclerotherapy B) Metoprolol C) Nadolol D) Repeat endoscopy Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.