单选题
The phrase “if not possible, advise” may be used together with the clearance or instruction ( ) .
A
when the controller is in doubt about the capability of the pilot in complying with the clearance or instruction
B
after an alternative clearance or instruction is offered
C
if the controller is sure that the pilot cannot comply with the clearance or instruction
D
when the controller is not ready to help the pilot
答案解析
正确答案:A
