Check all the correct answers. Select one or more: O a. Given the following code snippet: string s1("aa"), s2("bb"), s3; s3 = S1 + S2; The following function prototype can't be used for the above operator+ : string opertor+( string, string); O b. Given the following code snippet: int x=5, y=0; y = ++x; The function prototype of the above operator++ is as follows: int operator++( int& ); O c. C++ allows a program to overload an operator. O d. Given the following code snippet: double x=10.00, y=11.00, z=0; z = x - y: The function prototype of the above operator- is as follows: double operator-( double, double); A C++ program declares the following two variables, select all the answers that apply: char orgName1[100] = "United Nations"; string orgName2( "United States"); Select one or more: a. Unlike orgName1, orgName2 can be modified to store as many characters as long as it does not exceed its maximal size allowed by the compiler. b. To compare orgName2 with orgName3 defined below: string orgName3 ("the u.s.a."); We can do the following: if (orgName2==orgName 3) //other code goes here c. orgName2 is an object-oriented string object. It's equipped with a large collection of member functions, e.g., at() and size(). d. orgName1 is a fixed-size array of characters. It should be used to hold at most 99 characters