The diagram shows changes of pressure during the cardiac cycle.

Which is an explanation of the processes happening?

A. During phase I, pressure in the left ventricle decreases while it increases in the aorta during contraction of the left atrium.
B. In phase II, pressure rises in the aorta because the left ventricle is contracting.
C. In phase III, pressure decreases in the aorta because the left atrium is relaxing.
D. In phase III, there is a constant increase of pressure in the aorta as both left atrium and ventricle are at rest.

B

This question discriminated very well.