Question: How can we make a class abstract?
[A]. By making all member functions constant.
[B]. By making at least one member function as pure virtual function.[C]. By declaring it abstract using the static keyword.
[D]. By declaring it abstract using the virtual keyword.
[B]. By making at least one member function as pure virtual function.[C]. By declaring it abstract using the static keyword.
[D]. By declaring it abstract using the virtual keyword.
Answer: Option B