如下程序的运行结果是()。#includevoid sub();int main(){ int a,b; a=3; b=4; printf(“main中,调用sub前:a=%d,b=%d”,a,b); sub(); printf(“main中,调用sub后:a=%d,b=%d”,a,b);}void sub(){ int a, b; a=6; b=7; printf(“sub中:a=%d,b=%d
A.main中,调用sub前:a=3,b=4sub中:a=6,b=7调用sub后:a=3,b=4 B.main中,调用sub前:a=3,b=4sub中:a=6,b=7调用sub后:a=6,b=7 C.main中,调用sub前:a=3,b=4调用sub后:a=6,b=7sub中:a=6,b=7 D.main中,调用sub前:a=3,b=4调用sub后:a=3,b=4sub中:a=6,b=7