Ace Your C++ Skills 2025 – Rock the ‘Thinking in C++’ Challenge!

A base class function declaration serves as a template for potential derived classes to inherit and implement in their own unique ways.

The "virtual" keyword is necessary to ensure dynamic dispatch, which allows the correct implementation of the function to be called at runtime based on the actual type of object being referenced. This enables polymorphism, which is essential for creating different behaviors for different derived classes. Option A and B do not pertain to the concept of polymorphism and are not necessary for base class function declaration. Option D, "const," is not necessary for allowing polymorphism and instead pertains to the constantness of a variable.