What does it mean if a program is said to be modular?

A program described as being modular means that it is structured by breaking down its functionality into independent sub-programs, known as modules. This design approach promotes organization and clarity within the codebase, allowing developers to divide complex tasks into smaller, manageable pieces. Each module can focus on a specific aspect of the program's functionality, such as data processing, user interface management, or database interactions.

This independence allows modules to be developed, tested, and maintained separately, which enhances collaboration among programmers and makes the overall software development process more efficient. Additionally, modular programs can be easily updated or enhanced by adding new modules or modifying existing ones without needing a complete overhaul of the entire system. This aspect greatly supports maintainability and scalability.

In contrast, the other options either misunderstand the concept or provide details that contradict the properties associated with modular programming. For example, a program that can run without any modules does not exemplify modular design, as the essence of modularity is the presence of distinct components that can function independently while contributing to the overall application.