Answer is B in my opinion
Ventricular systole is when the ventricles of the heart as the result of electrical activity which helps to pump blood. During ventricular systole oxygenated blood is pumped from the left ventricle through the aortic valve and aorta. Simultaneously deoxygenated blood is pumped from the right ventricle through the pulmonic valve and pulmonary artery to the lungs. Using this explanation blood enters the aorta and pulmonary artery during ventricular systole. <span />
The correct answer would be D, gravity. As moving water will cause rocks to erode as well as wind, and animal habitation.
