Final answer:
Statins reduce the risk of coronary heart disease by lowering cholesterol levels in the blood, which helps to prevent the formation of arterial plaque and subsequent blockages.
Step-by-step explanation:
Statins are a class of drugs commonly prescribed to individuals at risk of coronary heart disease (CHD). These medications function by inhibiting the enzyme HMG-CoA reductase, which is responsible for the synthesis of cholesterol from lipids within the body. As statins reduce the activity of this enzyme, the levels of cholesterol produced in the body are decreased, leading to lower cholesterol levels in the blood.
Reducing blood cholesterol is crucial because it helps to prevent the build-up of plaque (atherosclerosis) in the coronary arteries, which can impede blood flow to the heart muscle and increase the risk of heart attacks. So, in answer to the student's question, statins primarily lower cholesterol levels in the blood (A), and as a consequence, they help prevent arterial blockages (B), thereby substantially reducing the risk of coronary heart disease.