A patient with cardiogenic shock requires an Intra-Aortic Balloon Pump (IABP). Which statement best describes the role of the balloon during diastole?

A. The balloon inflates to increase coronary perfusion: During diastole, the intra-aortic balloon inflates, which displaces blood toward the coronary arteries. This increases perfusion to the myocardium, improving oxygen delivery to ischemic heart tissue, which is critical in cardiogenic shock where myocardial oxygen supply is compromised. B. The balloon deflates to reduce afterload: Deflation of the balloon occurs just before systole, not during diastole. Rapid deflation reduces aortic pressure and afterload, decreasing left ventricular workload and myocardial oxygen demand, but this is a systolic, not diastolic, effect. C. The balloon inflates to decrease myocardial oxygen demand: Inflating during diastole primarily improves coronary perfusion rather than reducing oxygen demand. Oxygen demand is reduced indirectly during systolic deflation by lowering afterload. D. The balloon inflates to increase cardiac output directly: While IABP therapy can improve cardiac output, inflation during diastole does so indirectly by enhancing myocardial oxygen supply. The balloon does not actively eject blood to increase cardiac output; the effect is supportive rather than direct.