Explain what a destructor is and why it cannot be overloaded.

What will be an ideal response?

A destructor contains the actions you require when an instance of a class is destroyed. Most often, an instance of a class is destroyed when it goes out of scope. As with constructors, if you do not explicitly create a destructor for a class, C# automatically provides one.
To explicitly declare a destructor, you use an identifier that consists of a tilde (˜) followed by the class name. You cannot provide any parameters to a destructor; it must have an empty argument list. As a consequence, destructors cannot be overloaded; a class can have one destructor at most.