Which of these classes defined in java.io and used for file-handling are abstract?
A. InputStream
B. PrintStream
C. Reader
D. FileInputStream
E. FileWriter

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