11. consider the following skeletal c program: void fun1(void); /* prototype */ void fun2(void); /* prototype */ void fun3(void); /* prototype */ void main() { int a, b, c; . . } void fun1(void) { int b, c, d; . . } void fun2(void) { int c, d, e; . . } void fun3(void) { int d, e, f; . . }