Question ID:PT28 S1 Q26 Passage: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. Stem:Which one of the following, if true, LEAST strengthens the argument above? Correct Answer Choice:EChoice A:After the laptop computer was turned off, the plane regained course and its navigation instruments and dials returned to normal. Choice B:When in use all electronic devices emit electromagnetic radiation, which is known to interfere with circuitry. Choice C:No problems with navigational equipment or instrument dials have been reported on flights with no passenger-owned electronic devices on board. Choice 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. Choice E:Planes were first equipped with low-power circuitry at about the same time portable electronic devices became popular.