What will be the output of the following Java program?

class output
{
    public static void main(String args[])
    { 
       StringBuffer s1 = new StringBuffer("Hello");
       s1.setCharAt(1,x);
       System.out.println(s1);
    }
}

A. Scanner B. FileReader C. BufferedReader D. InputStream

A. It performs mathematical operations B. It writes data to a file C. It reads data from the keyboard D. It prints data to the standard output stream followed by a newline

A. read() B. print() C. write() D. scan()

A. By using the `terminate()` method B. By using the `close()` method of the file stream C. By using the `readLine()` method D. By using the `exit()` method