Which of the following terms are used to describe defining a class so that the implementation of the member functions is either not known or at least is irrelevant to its use

a. walling up
b. encapsulation
c. abstraction
d. Caging up the data and functions
e. Information hiding

The terms used in the text are b) c) and e).
Explanation: Each of these terms mean that the details of the implementation of the functions is hidden from the client programmer (the programmer who uses the class). The text prefers encapsulation.