Which of the following statements is false?

a. InputStream and OutputStream are abstract classes for performing byte-based I/O.
b. Tubes are synchronized communication channels between threads.
c. A filter stream provides additional functionality, such as aggregating data bytes into meaningful primitive-type units.
FilterInputStream and FilterOutputStream are typically extended, so some of their filtering capabilities are provided by their
concrete subclasses.
d. A PrintStream performs text output. System.out and System.err are PrintStreams.

b. Tubes are synchronized communication channels between threads.