A. If it is not a macro, it may evaluate stream more than once
B. if it is amacro, it may not evaluate stream more than once
C. if it is a macro, it may evaluate stream more than once
D. no difference between fgetc() and getc()

Solution

C. if it is a macro, it may evaluate stream more than once

Explanation

getc() is equivalent to fgetc() except that if it is a macro, it may evaluate more than once.