Using the "Grind 'Em and Find 'Em" Strategy, a Scientist

Using the "grind 'em and find 'em" strategy, a scientist finds eight promising chemicals that can control the growth of cancer cells in the lab. However, the only one that is useful as a drug for humans

A) kills normal cells as well as cancer cells.
B) is stable in the human body.
C) is difficult to manufacture in a laboratory.
D) is very expensive to gather.