You are answering a USMLE-style medical question. Question: A 41-year-old man is brought to the emergency department after a suicide attempt. His wife found him on the bathroom floor with an empty bottle of medication next to him. He has a history of major depressive disorder. His only medication is nortriptyline. His pulse is 127/min and blood pressure is 90/61 mm Hg. Examination shows dilated pupils and dry skin. The abdomen is distended and there is dullness on percussion in the suprapubic region. An ECG shows tachycardia and a QRS complex width of 130 ms. In addition to intravenous fluid resuscitation, which of the following is the most appropriate pharmacotherapy? Options: A) Naloxone B) Cyproheptadine C) Ammonium chloride D) Sodium bicarbonate Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.