Why is it recommended to declare a virtual destructor in a base class? (2 Points) a) To prevent memory leaks b) To allow dynamic casting c) To ensure proper destruction of derived class objects d) To make the destructor public

The main reason to declare a virtual destructor in a base class is to ensure proper destruction of derived class objects (option c).

Here's a step-by-step explanation:

1. In C++, when a derived class object is deleted through a pointer to a base class that has a non-virtual destructor, results are undefined.

2. This is because the base class's destructor does not know about the derived class and its members, so it cannot properly delete them. This can lead to memory leaks (option a), as the memory allocated for the derived class object is not freed.

3. Declaring a virtual destructor in the base class ensures that the derived class's destructor is called when an object is deleted through a base pointer, which allows for proper cleanup of the derived class object.

4. This has nothing to do with allowing dynamic casting (option b) or making the destructor public (option d). A destructor can be virtual regardless of its access specifier (public, protected, or private), and dynamic casting is related to runtime type identification, not object destruction.