59.
Certain messenger molecules fight damage to the lungs from noxious air by telling the muscle cells encircling the lungs’ airways to contract. This partially seals off the lungs. An asthma attack occurs when the messenger molecules are activated unnecessarily, in response to harmless things like pollen or household dust.

Which of the following, if true, points to the most serious flaw of a plan to develop a medication that would prevent asthma attacks by blocking receipt of any messages sent by the messenger molecules referred to above?

(A) Researchers do not yet know how the body produces the messenger molecules that trigger asthma attacks.
(B) Researchers do not yet know what makes one person’s messenger molecules more easily activated than another’s.
(C) Such a medication would not become available for several years, because of long lead times in both development and manufacture.
(D) Such a medication would be unable to distinguish between messages triggered by pollen and household dust and messages triggered by noxious air.
(E) Such a medication would be a preventative only and would be unable to alleviate an asthma attack once it had started.

题干的意思有点迷糊，哪位NN能帮我解释一下？

为了防止肺部遭受毒气损伤，一些messenger molecules会让环绕肺部通气管周围的肌肉收缩。这样可以使得肺部部分封闭。但是，如果这些messenger molecules过于敏感，甚至对于像花粉和灰尘这样的无害物也起反应时，人们就会得哮喘。

问题看的懂吧。