The credit card mobile phones now provided on some aircraft, do not interfere with aircraft systems because they are wired to a special "base station" that has been designed to safely receive and transmit radio signals in the aircraft.
Does this next sentence follow, given the preceding text?
Captains can use credit card mobile phones for free

Pick from:
(a). Yes.
(b). It's impossible to say.
(c). No.
(b).