Question on Constructors

[majohnad majohnad]

In regard to constructors, how can you prevent a class from being instantiated?
A. Use the private declaration.
B. Use anonymous classes.
C. Employ overloading.
D. Use only static inner classes.
the answer is given as A, why can't be B.
Thanks in Advance.

[Lawrence Chettiar]

The answer is A coz you if you use anonymous classes only you can instantiate it & use it in the class you defined etc. (note you can still instantiate it.) secondly its not a top level class all questions should be assumed as top level class question until specified otherwise(As per my experience in all mock exams)
Again to explain in detail say if you take the static class example java.lang.Math class you can't make a instance of this class as the constructor is private.
Its a normal practice to create such classes for Util methods.