[求助]FeiFei宝典的问题（关于LEAST STRENGTHEN）

FeiFei宝典No.18如下

18. Modern navigation systems, which are found in most of today’s commercial aircraft, are made with low-power circuitry, which is more susceptible to interference than the vacuum-tube circuitry found in older planes. During landing, navigation systems receive radio signals from the airport to guide the plane to the runway. Recently, one plane with low-power circuitry veered off course during landing, its dials dimming, when a passenger turned on a laptop computer. Clearly, modern aircraft navigation systems are being put at risk by the electronic devices that passengers carry on board, such as cassette players and laptop computers.

Which one of the following, if true, LEAST strengthens the argument above?

(A) After the laptop computer was turned off, the plane regained course and its navigation instruments and dials returned to normal.

(B) When in use all electronic devices emit electromagnetic radiation, which is known to interfere with circuitry.

(C) No problems with navigational equipment or instrument dials have been reported on flights with no passenger-owned electronic devices on board.

(D) Significant electromagnetic radiation from portable electronic devices can travel up to eight meters, and some passenger seats on modern aircraft are located within four meters of the navigation systems.

(E) Planes were first equipped with low-power circuitry at about the same time portable electronic devices became popular.

5个选项，A,B,D直接加强，C间接加强（较弱），E为无关选项，答案为E。

想问的是，题目问题是LEAST strengthens the argument，E项为No Strenghen at all 故= Least strenthen ？

无关的就是Least strenthen？而不是要在所有加强选项里选一个理由最弱的？

那以后碰到这种LEAST strengthen题，如果选项里出现了Weaken选项是不是该选？

我感觉这种题的选项一般有四个都是加强

剩下那个是无关或削弱，即是答案