Thread: virtual destructors

The answer is D, and to understand why read this FAQ answer: When should my destructor be virtual?

The idea behind virtual is the polymorphic concept.
If you create a new instance of a derived class and put it inside a pointer to its base class and call functions through that pointer, the compiler will call the base class's functions, even though a derived function may already exist. This is because the compiler doesn't know the pointer is actually pointing to a derived class instance.
Now, if you would make that function virtual, the compiler will "look up" the correct type and call the appropriate function, in this case, the derived function if it exists, or the base class's, if it does not.

The same applies to the destructor.
The destructor by the compiler when an object is destroyed.

So with that knowledge in mind, the answers to these questions are:
A) Incorrect, because the derived constructor will always be called when a derived object is destroyed.
B) Incorrect, because it makes no sense. Virtual does not "steal" a function call.
C) Incorrect, because of the same reason as A).
D) Correct, because if delete is called on a pointer to the base class, ONLY the base class's constructor will be called (since the compiler thinks it's a Base class object the pointer is pointing to). Making it virtual fixes this because of the discussion above.
E) Incorrect, as you say.