GATE | CSE 2023 | Question 37

Consider the following program

int main()     int f1(){                int f2(int X){                   int f3(){
{                 return (1);            f3();                             return (5);
f1();           }                       if(X==1)                          }
f2(2);                                     return f1();
f3();                                   else
return(0);                                 return (X+f2(X-1));
}                                        }

Which of the following options represents the activation tree corresponding to the main function?

(A)

(B)

(C)

(D)