In the context of programming, what does a module typically include?

A module serves as a discrete unit of code that can include a variety of elements integral to programming. The correct choice encompasses functions, classes, variables, and runnable code, reflecting the comprehensive nature of what a module can contain.

Functions are reusable blocks of code that perform specific tasks, enabling modularity and reducing redundancy. Classes provide the foundational blueprint for creating objects, encapsulating both data and behavior, which is essential for object-oriented programming. Variables can store data values that are accessed and modified throughout the module. Lastly, runnable code refers to code that is designed to execute and can often initiate processes or algorithms directly within the module.

This combination of components allows for better organization, maintenance, and readability of code, all critical aspects in developing effective programming practices. In contrast, the other options represent a more limited view of what constitutes a module, which could lead to less flexible code architectures.