Which of the following is the action of Diltiazem?

Correct option is B

Diltiazem is a calcium channel blocker. It works by inhibiting the influx of calcium ions into smooth muscle and cardiac muscle cells, leading to vasodilation and decreased heart rate. It is commonly used to treat hypertension, angina, and certain types of arrhythmias.
Explanation of options: (a) ✘ Incorrect. Stimulants increase activity in the body, but Diltiazem is a depressant of cardiac function. (b) ✔ Correct. Calcium channel blockers like Diltiazem block calcium entry into cells, reducing heart rate and relaxing blood vessels. (c) ✘ Incorrect. Beta-blockers work by blocking beta receptors, not calcium channels. (d) ✘ Incorrect. Sedatives and hypnotics are used to calm or induce sleep, but Diltiazem has a different mechanism of action.