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

#include<iostream>
using namespace std;
class Test
{
   private:
     static int count;
   public:
     Test& fun(); 
};
int Test::count = 0;
Test& Test::fun()
{
    Test::count++;
    cout << Test::count << " ";
    return *this;
}
int main()
{
    Test t;
    t.fun().fun().fun().fun();
    return 0;
}

A. 4 4 4 4

B. 1 2 3 4

C. 1 1 1 1

D. 0 1 2 3

Answer: Option B