During the cardiac cycle heart sounds correlate with events of the cycle. Which is being associated with systole?

A. S3: This sound is associated with early diastole, often related to heart failure or volume overload. B. S1: The first heart sound (S1) marks the beginning of systole and corresponds to the closure of the mitral and tricuspid valves. C. S2: The second heart sound (S2) indicates the end of systole and the beginning of diastole, associated with the closure of the aortic and pulmonic valves. D. S4: This sound is associated with late diastole, often related to decreased ventricular compliance.