The number of airplanes equipped with a new anti collision device has increased steadily during the past 2 years. during the same period, it has become increasingly common for key information about an airplane's altitude and speed to disappear suddenly from the air traffic controller's screen. The new anti collision device, which operates at the same frequency as air traffic radar, is therefore responsible for the sudden disappearance of key information.
Which one of the following if true most seriously weakens the argument?
A> The anti collision has already prevented a number of accidents.
B> It was not until the new anti collision device was introduced that key info first began disappearing.
C> The new anti collision device is scheduled to be moved to a different frequency
D> Key information began disappearing from controllers screens three months before the new anti collision device was first used
E> The sudden disappearance of key information from controllers screen has occurred only at relatively large airports.
I want to ask that why is E wrong. Right now we have Cause A ( anti collision device) --> Effect ( info disappear) . But if we can provide and alternative cause B ( something to do with large airports) to the same effect ( info disappear)... then doesn't it weaken the argument?
Which one of the following if true most seriously weakens the argument?
A> The anti collision has already prevented a number of accidents.
B> It was not until the new anti collision device was introduced that key info first began disappearing.
C> The new anti collision device is scheduled to be moved to a different frequency
D> Key information began disappearing from controllers screens three months before the new anti collision device was first used
E> The sudden disappearance of key information from controllers screen has occurred only at relatively large airports.
I want to ask that why is E wrong. Right now we have Cause A ( anti collision device) --> Effect ( info disappear) . But if we can provide and alternative cause B ( something to do with large airports) to the same effect ( info disappear)... then doesn't it weaken the argument?
