Question ID:PT26 S2 Q11 Passage:Commercial passenger airplanes can be equipped with a collision-avoidance radar system that provides pilots with information about the proximity of other airplanes.  Because the system warns pilots to take evasive action when it indicates a possible collision, passengers are safer on airplanes equipped with the system than on comparable airplanes not so equipped, even though the system frequently warns pilots to evade phantom airplanes. Stem:Which one of the following, if true, most strengthens the argument? Correct Answer Choice:AChoice A:Evasive action taken in response to the system's warnings poses no risk to the passengers. Choice B:Commercial passenger airplanes are in greater danger of colliding with other airplanes while on the ground than they are while in flight. Choice C:Commercial passenger airplanes are rarely involved in collisions while in flight. Choice D:A study by ground-based air traffic controllers found that 63 percent of the warnings by the system were invalid. Choice E:The collision-avoidance radar system is run by a computerized device on the plane that scans the sky and calculates the distances between planes.