Suppose obj1 and obj2 are two objects of a user defined class A. An + operator is overloaded to add obj1 and obj2 using the function call obj1+obj2. Identify the correct function prototype against the given call?

(A) A operator + ( A &obj);
(B) int + operator();
(C) int operator (plus) ();
(D) A operator(A &obj3);