What will be the output of the following C++ code?

#include <iostream>
using namespace std;
#define PI 3.14159
int main ()
{
    float r = 2;
    float circle;
    circle = 2 * PI * r;
    cout << circle;
    return 0;
}

A. A variable that stores the size of another variable B. A variable that stores the address of another variable C. A variable that stores a reference to another variable D. None of the above

A. ptr *type; B. type ptr; C. type *ptr; D. ptr type;

A. Address of x B. Garbage value C. Compilation error D. 5

A. *ptr B. ptr* C. &ptr D. ptr