Question: What is a copy constructor?

1. It is a unique constructor for creating a new object as a copy of an object that already exists. There will always be only one copy constructor that can be either defined by the user or the system.
2. It is a constructor that duplicates itself when requested on demand.
3. It is a common constructor for preventing the creation of a new object as a copy of an object that already exists. There will always be multiple standard constructors that can be either defined by the user or the system.
4. It is a constructor that duplicates itself on its own, based on memory available.

Answer: The correct answer of the above question is Option A:It is a unique constructor for creating a new object as a copy of an object that already exists. There will always be only one copy constructor that can be either defined by the user or the system.