Which option best describes aortic valve insufficency?

A. Aortic valve insufficiency is when the aortic valve closes too tightly, restricting blood flow.

B. Aortic valve insufficiency is a condition where the aortic valve is located in the right ventricle.

C. Aortic valve insufficiency is a term used to describe a blockage in the pulmonary artery.

D. Aortic valve insufficiency is when the aortic valve does not close properly, causing blood to leak back into the left ventricle.