How do calcium channel blockers contribute to lowering blood pressure?

Calcium channel blockers are effective antihypertensive agents primarily due to their ability to cause vasodilation and decrease heart contractility. These drugs operate by inhibiting the influx of calcium ions into both vascular smooth muscle cells and cardiac muscle cells through voltage-gated calcium channels.

By preventing calcium from entering these cells, calcium channel blockers induce relaxation of the vascular smooth muscle, leading to dilation of blood vessels. This vasodilation directly reduces peripheral vascular resistance, which in turn lowers blood pressure. Additionally, the reduction of calcium entry into cardiac muscle cells results in decreased contractility, or myocardial contractile strength. This dual action not only causes the blood vessels to relax but also reduces the workload on the heart, further contributing to lower blood pressure levels.

Thus, option B correctly highlights the mechanisms through which calcium channel blockers exert their antihypertensive effects.