\begin{tabular}{l}{\( [C++11]: \) To help prevent errors, apply \( C++11 \) 's } \\ keyword to the prototype of every \\ derived-class function that overrides a base- \\ class virtual function. \\ abstract \\ None of the above. \\ virtual \\ override \\ \hline\end{tabular}

C++11 introduced the `override` keyword, which enhances code clarity and safety. By adding `override` to a derived class function that is meant to override a virtual function from a base class, the compiler will check to ensure that the function actually overrides a base-class function. If there is a mismatch in the function signature, the compiler will produce an error, helping developers catch potential issues early in the development process. In practice, using the `override` keyword can significantly reduce bugs related to virtual function overrides, especially in large codebases. It serves as a clear signal to anyone reading the code that the function is intended to override a base class method. So the next time you're working in C++, just remember to sprinkle in `override` for that extra dash of reliability to your class hierarchies!