Answer: a. Testosterone
Explanation: Testosterone is the primary male sex hormone and anabolic steroid. In male humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of body hair. Women have little testosterone in them too but to much testosterone in women leads to frontal hair loss, balding, deepening of voice, developing muscles and enlarges the most sensitive part of the woman body. But since Nicole's Doctor would be the one administering it to Nicole as a form of treatment to her dysfunctional sexual life, she will regulate it in doses that will enhance and increase her sexual urges. Recall, the hormone increases the size of the most sensitive part in the female. It gives them great pleasure when it is stimulated.