B. To use a comparison to explain the way a heart functions.
Explanation:
Human heart is not ideally a pump but for a surgeon to use pump to describe the functioning of the heart is to draw home the least likely possibility of how the heart works.
The heart regulates the distribution of blood along the various organs and parts of the body through the circulatory system. Supply oxygen and nutrients, while removing carbon dioxide and wastes.
well is he greedy or not? if he is than you have two choices, A. and D. if he is judgmental then the answer is C. if he is kind then the answer would be B, overcoming circumstances to act morally.