Hey, people. Let’s get into this! We’re essentially looking for something that doesn’t do a good job of strengthening the passage.
(A) After the laptop computer was turned off, the plane regained course and its navigation instruments and dials returned to normal.
Not what we’re looking for since this does a good job. If the plane’s navigation stuff returned to normal AFTER the laptop was turned off, that would lend support that electronic devices such as laptops could be doing something negative (i.e. when they’re taken onboard and turned on).
(B) When in use all electronic devices emit electromagnetic radiation, which is known to interfere with circuitry.
Nope. This provides a strong and precise explanation for how modern planes with low power circuitry (which is more vulnerable than vacuum-tube circuitry in older planes) could be negatively affected by electronic devices that passengers carry on board.
(C) No problems with navigational equipment or instrument dials have been reported on flights with no passenger-owned electronic devices on board.
Nope. If flights with zero passenger electronic devices have never reported problems with their navigational stuff, this would lend support that electronic devices are to blame when they do occur when onboard.
(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.
Not what we’re looking for. This strengthens the argument pretty well if we’re told that some passenger seats (and therefore electronic devices passengers may sit with) are close enough to cause significant electromagnetic radiation to the navigation systems of the plane.
(E) Planes were first equipped with low-power circuitry at about the same time portable electronic devices became popular.
This is the answer. Just because two things happened around the same time doesn’t necessarily confirm in a powerful way that electronic devices were to blame, for example, for what happened to the plane in the passage. Neither the passage nor this answer choice describe an ongoing pattern or a strong causational link or reason that blames electronic devices for issues with the navigational stuff.