What is the standard form of identification you might ask a passenger to present when issuing an international flight ticket？

What is the standard form of identification you might ask a passenger to present when issuing an international flight ticket？
A.A library card.
B.A driver's license （for international flights）.
C.A valid passport.
D.A gym membership card.
正确答案：C
试题解析：国际航班通常要求乘客出示有效护照作为身份识别的标准证件，以确保乘客身份真实及符合出入境要求。