What Is the Output of the Following Program?
#Include ≪iostream> $\quad$

What is the output of the following program?
#include <iostream>
using namespace std;
class TestClass
{
Public:
$\quad$ TestClass(int x)
$\quad$ { cout << x << endl; }
$\quad$ TestClass()
$\quad$ { cout << "Hello!" << endl; }
};
int main()
{
$\quad$ TestClass test(77) ;
$\quad$ return 0;
}

A) the program runs but there is no output.
B) 77
C) Hello!
D) the program will not compile