Beta Blockers USMLE Step 1 Practice Question

A 48-year-old man with a history of poorly controlled hypertension presents to the emergency department with sudden onset tearing chest pain radiating to his back. CT angiography confirms a Stanford Type A aortic dissection, and he is admitted to the intensive care unit where an intravenous antihypertensive medication is initiated to achieve a target systolic blood pressure below 120 mmHg. After 72 hours of high-dose infusion, the nursing staff notes he has become acutely confused and agitated. Repeat laboratories reveal a pH of 7.18, lactate of 8.2 mmol/L, and an elevated anion gap. Notably, one staff member detects a faint odor of bitter almonds near the patient's bedside. Which of the following drugs most likely caused this complication?