2. Consider the following skeletal C program: void funL(void); prototype oid fun2ivoid);/ prototype void fun3(void): prototype void main() { int a, b, C void funL(void) ( int b, c, d; void fun2(void) int c, d, e; oid fun3void) ( int d, e, f Given the following calling sequences and assuming that dynamic scoping is used, what variables are visible during execution of the last function called? Include with each visible variable the name of the function in which it was defined a. main calls fun1; fun1 calls fun3. b. main calls fun3; fun3 calls fun2