why DoEs nigEl suggEst thAt BusinEss trAvEllErs AvoiD Big AirportsA．BECAusE All Flights in AnD out oF thErE ArE Full.
B、BECAusE thE volumE oF trAFFiC is hEAvy.
C．BECAusE thErE ArE morE populAr Flights.
D．BECAusE thErE ArE morE DElAys AnD CAnCEllAtions.