Ventricular Systole: Key Cardiac Phase Steps:

• Identify ventricular systole as the contraction phase of the ventricles in the mammalian heart.
• Recall that this raises ventricular pressure above atrial pressure, closing AV valves (first heart sound).
• Note semilunar valves open as ventricular pressure exceeds arterial pressure, ejecting blood.
• Confirm atria are relaxed (diastole), so no atrial contraction or open AV valves occur.

Why D is correct:

• Ventricular systole involves only semilunar valve opening and blood ejection (statement 3), per cardiac cycle physiology.

Why the others are wrong:

• A and B include incorrect statements (1 and/or 2, likely atrial contraction or AV valve opening, which occur in atrial systole).
• C includes only statement 2, which is inaccurate for this phase.

Not enough information on exact statements 1–3, but D aligns with standard events.

Final answer: D