Answer:
The correct answer is D.
Explanation:
During cardiac cycle, when the left ventricle is full, mitral valve closes to prevent blood to flow backwards into the atrium while the ventricle contracts. This is the end of diastole and the beginning of systole.
The left ventricle contracts and blood flows through aortic valve into the aorta and to de body. The closure of aortic valve establishes systole end.
