What does the process of preprocessing involve in C++ programming?

Preprocessing in C++ programming is an essential first step that occurs before the actual compilation of the code begins. This process primarily involves handling directives that are indicated by the '#' symbol. One of its main functions is to expand macros, which are used to define snippets of code that can be reused throughout the program. This means that whenever a macro is invoked in the code, the preprocessor substitutes it with the defined content.

Additionally, preprocessing includes including files, which allows for the modularization of code. By including header files, programmers can use declarations and definitions contained within those files, promoting code reuse and organization. This enables developers to manage large code bases more effectively.

By performing these tasks—macro expansion and file inclusion—the preprocessor prepares the code for the compiler, making this option the most accurate representation of what preprocessing entails in C++.