Which statement best describes the relationship between defining a function and calling it?

The correct answer encompasses the foundational concepts of functions in programming. Defining a function and calling it are two distinct but interconnected steps in the development process.

A function must be defined before it can be called; this is essential because the programming language needs to understand what the function does and how it is structured before there can be any attempt to execute it. If a function is called before its definition, the program will result in an error as it will not recognize the function's name or behavior.

Additionally, a function can indeed be defined multiple times within a single file. However, this is usually not recommended as it can lead to confusion or errors, particularly if the function definitions differ. Multiple definitions might overwrite previous ones, affecting the functionality.

Moreover, a function can be called multiple times throughout the same file. This feature is particularly useful for code reuse and makes it easier to maintain and execute repetitive tasks without writing the same code multiple times.

Thus, understanding that functions can be defined multiple times, called multiple times, and must be defined prior to being called is essential, which is why the comprehensive answer includes all these points.