Critical Reasoning

Certain molecules prepare a person to engage in "fight or flight" in response to danger by stimulating the adrenal glands to make adrenaline, which in turn produces a cascade of responses that includes increased demand on the heart and raised blood pressure. In some people, these molecules are easily activated by common, but not dangerous, situations, increasing their risk of developing heart disease and hypertension.

Which of the following, if true, points to the most serious flaw of a plan to develop a medication that would block the molecules referred to above from stimulating the adrenal glands?


(A) Such a medication would indiscriminately block these molecules, whether they are activated by situations that are dangerous or not dangerous.
(B) Such a medication will not be available for many years due to the lengthy testing and approval process.
(C) Scientists have not yet discovered why these molecules are more easily activated for some people than for others.
(D) Such a medication will reduce a person's risk of developing heart disease but will not protect that person from developing hypertension.
(E) This medicine will have no discernible effect on people for whom these molecules are not easily activated by common situations.