When things far away seem indistinct, one is probably ______.

A．is in favor of prohibiting passengers' use of electronic devices completely
B．regards it as unreasonable to exercise a total ban during flight
C．hasn't formed his own opinion on this problem
D．has overestimated the danger of electromagnetic interference

A．They may have been caused by the damage to the radio systems.
B．They may have taken place during take - off and landing.
C．They were proved to have been caused by the passengers' portable computers.
D．They were suspected to have resulted from electromagnetic interference.