<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 65-year-old male with a history of hypertension presents to his primary care physician complaining of multiple episodes of chest pain, palpitations, and syncope. Episodes have occurred twice daily for the last week, and he is asymptomatic between episodes. Electrocardiogram reveals a narrow-complex supraventricular tachycardia. He is treated with diltiazem. In addition to its effects on cardiac myocytes, on which of the following channels and tissues would diltiazem also block depolarization?? A: L-type Ca channels in skeletal muscle, B: L-type Ca channels in smooth muscle, C: P-type Ca channels in Purkinje fibers, D: N-type Ca channels in the peripheral nervous system, E: T-type Ca channels in bone,  <response>: This is a medical question asking about the mechanism of action of diltiazem, a calcium channel blocker used to treat supraventricular tachycardia. The question stem describes a patient case of supraventricular tachycardia that is treated with diltiazem. It asks which channels and tissues diltiazem would block depolarization in, in addition to cardiac myocytes. To answer this, we need to know that diltiazem is an L-type calcium channel blocker. L-type calcium channels are found in cardiac myocytes, smooth muscle cells, and skeletal muscle cells. Diltiazem blocks these channels, preventing calcium influx and subsequent depolarization.So the correct answer should indicate that diltiazem blocks L-type calcium channels in both cardiac myocytes and smooth muscle.B: L-type Ca channels in smooth muscle 