The word "aggressiveness" in the second sentence of the first paragraph is closest in meaning to " ________".

A．to explain the specific functions of various hormones
B．to provide general information about hormones
C．to explain how the term "hormone" evolved
D．to report on experiments in endocrinology

A．The human body requires large amounts of most hormones.
B．Synthetic hormones can replace a person's natural supply of hormones if necessary.
C．The quantity of hormones produced and their effects on the body are related to a person's age.
D．A short child of tall parents very likely has a hormone deficiency early in life.