Which of the following overloaded functions are NOT allowed in C++?1) Function declarations that differ only in the return type int fun(int x, int y); void fun(int x, int y); 2) Functions that differ only by static keyword in return type int fun(int x, int y); static int fun(int x, int y); 3)Parameter declarations that differ only in a pointer * versus an array []int fun(int *ptr, int n);int fun(int ptr[], int n); 4) Two parameter declarations that differ only in their default argumentsint fun( int x, int y); int fun( int x, int y = 10); (A) All of the above(B) All except 2)(C) All except 1)(D) All except 2 and 4