请教前辈！

最近做一习题，小人愚笨，百思不得其解，请教各位。

As a part of delicately balanced system, the human heart secretes a hormone, a substance that controls the amount of salt in the blood and volume of blood circulating within the body. Only very small quantities of the hormone are required. This hormone is extremely important in regulating blood pressure and is found in large amounts in the blood of those suffering a heart attack.

If the statement above are true, then it must also be true that

A. If there is a deficiency in the amount of heart hormone secreted, low blood pressure will result.

B. it is large quantities of the heart hormone that cause heart attacks to occur.

C. the effects of a smal amount of the heart hormone will be long-lasting in the body.

D.if a device that is only a mechanical pump is used as an artificial heart, it will not perform all the functions of the human heart.

E. an drug that regualtes boold pressure will have its effect by influencing the amount of the heart hormone secreted.

我的答案是选B。可是正确答案偏偏是D。

题中说心脏病患者的血液中发现大量这种激素，由此推出心脏中有大量的这种激素将导致心脏病。这样推理不对吗？

我做过一些逻辑题，但老是觉得还没有入门，找不到那种做题的感觉。如果有哪位前辈，可以指出我做题思路的误区，小人将万分感激！！！

这是道GMAT的逻辑题，谢谢您！

A. "low blood pressure" is not indicated

B. no causual relationship indicated in the argument

C. the effect of "long-lasting" is not indicated

E. no causual relationship indicated in the argument

A. "low blood pressure" is not indicated

B. no causual relationship indicated in the argument

C. the effect of "long-lasting" is not indicated

E. no causual relationship indicated in the argument

A. "low blood pressure" is not indicated

B. no causual relationship indicated in the argument

C. the effect of "long-lasting" is not indicated

E. no causual relationship indicated in the argument