Which of the following statements about InputStream and Reader are correct? (Choose two.)

A. They are both abstract classes.

B. They can both be used to read character data.

C. One contains a read() method that returns a byte value, while the other contains a read() method that returns a char value.

D. They are both interfaces.

E. Only one of them contains a flush() method.

F. Only one of them contains a skip() method.