The organic nitrates relieve angina pain by veins and coronary arteries.

Explanation:

A. Headache is a common side effect of nitroglycerin due to vasodilation and can often be managed with continued use.

B. Nitroglycerin is known to cause headaches as a common side effect.

C. Taking nitroglycerin with a high-fat meal is not likely to prevent headaches; it may, in fact, delay absorption and onset of action.

D. A headache alone is not indicative of a serious allergic reaction to nitroglycerin; other symptoms would typically be present.

A. High cholesterol can lead to the buildup of plaque in the arteries, which can narrow the blood vessels and decrease blood flow to the heart, increasing the risk of heart disease.

B. High cholesterol does not directly damage the heart muscle but can contribute to conditions like atherosclerosis, which can affect heart function.

C. High cholesterol does not directly thicken the blood but can contribute to the formation of blood clots when combined with other factors.

D. High cholesterol does not typically interfere with the conduction system of the heart but can contribute to conditions like coronary artery disease.