Please give me short and concise answer to the above question.

Consider the following skeletal C program: void fun1 (void); / prototype / void fun2 (void); / prototype / void fun 3 (void); / prototype / void main () int a,b,c; vo. void fun 1 (void) int b,c,d; Given the following calling sequences and assuming that dynamic scoping is used, what variables are visible during the 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; fun 1 calls fun 2 ; fun2 calls fun 3. b. main calls fun 1; fun 1 calls fun 3 . c. main calls fun2; fun2 calls fun 3; fun 3 calls fun 1. d. main calls fun 3; fun 3 calls fun1. e. main calls fun1; fun1 calls fun 3; fun 3 calls fun2