Final answer:
The correct answer is C. right coronary artery; ischemia, as constriction of this artery would lead to decreased blood flow and potential damage to the heart muscle.
Step-by-step explanation:
Blood flow to the right side of the heart muscle decreases due to constriction of the right coronary artery, and decreased blood flow to the heart tissue can result in ischemia. Therefore, the correct answer to the question is C. right coronary artery; ischemia. The right coronary artery supplies the right side of the heart with oxygenated blood. When it is constricted or blocked, the heart muscle's blood supply is reduced, potentially leading to ischemia, which is a condition marked by inadequate blood flow to the cardiac muscle, causing damage or dysfunction of the tissue.
Constriction or blockage of the left coronary artery can lead to a myocardial infarction or heart attack, which is when an area of heart muscle dies or is permanently damaged due to lack of oxygen-rich blood. The other options, such as mitral valve prolapse and endocarditis, are irrelevant to the context given here.