Answer:
Const.
Step-by-step explanation:
In C++ programming language, if you wish to have your compiler deny or prevent access to a member function in modifying (changing) a calling object's private member variables in a line of code, you should declare the member as a const function. Therefore, the member function is simply declared as a constant by the compiler.
The word const at the end of several of the member functions in the accompanying class definition specifies that these functions cannot modify the member variables of a clockType object.