Which XXX (string stream) returns the following output?Hello John Denver #include #include #include using namespace std; int main() { string userInfo = "John Denver"; XXX string firstName; string lastName; inSS >> firstName; inSS >> lastName; cout << "Hello " << firstName << " " << lastName << endl; return 0; } a. istringstream inSS(userInfo); b. istringstream userInfo; c. inSS(userInfo); d. istringstream inSS