What is the error in the following code snippet?

void func(int a) {

a += 5;

return a;

}

int main()

{

func(3);

return 0;

}

a. Cannot change the value of variable a

b. The function cannot be called with a direct value such as 3

c. The function cannot return a value

d. Variable a must be declared in the function

18. What is the output of:

int *x;

int a = 5;

x = &a;

cout<<*x<<" "<

a. 5 0x444F

b. 5 5

c. 0x444F 5

d. 0x444F 0x444F

the answer is cb

please explain the answer. thanks so so much