Final answer:
Atherosclerosis is a condition in which artery walls thicken due to the buildup of plaques. It can result from various factors and can lead to restricted blood flow and serious complications. Option A is correct.
Step-by-step explanation:
Atherosclerosis is a condition in which artery walls thicken and stiffen as a result of the buildup of plaques inside the arteries. Plaques consist of white blood cells, cholesterol, and other fats. Typically, there is also a proliferation of smooth muscle cells that make the plaque fibrous as well as fatty.
Over time, the plaques may harden with the addition of calcium crystals. This reduces the elasticity of the artery walls. As plaques grow, they can narrow the artery, restricting blood flow and potentially blocking the blood vessel.
Atherosclerosis can occur due to multiple factors including a high-fat diet, high cholesterol levels, smoking, obesity, and diabetes. When plaque buildup prevents blood circulation in the heart or the brain, it can lead to serious conditions such as a heart attack or stroke.