A client with breast cancer is scheduled to undergo chemotherapy with aromatase inhibitors. Which of the following best reflects the rationale for using this group of drugs?
A) They lower the level of estrogen in the body blocking the tumor's ability to use it.
B) They block progesterone-dependent tumors from growing.
C) They attach to endogenous protein receptors to slow the growth of cancerous cells.
D) They stimulate the immune system to attack a protein common in many tumors.