What keyword is used to return control from a function back to the calling function?

The keyword used to return control from a function back to the calling function is 'return.' This keyword is critical in programming, especially in languages like C, C++, and Python, where functions are a central part of structuring the code and managing program execution flow. When 'return' is executed, it not only exits the function but can also return a value back to the point in the program where the function was called. This process allows for data to be passed from the function back to its caller, enabling effective communication and use of results within the program.

The other options, while relevant in programming, serve different purposes. 'goto' is used for jumping to another section of code arbitrarily, which can lead to unstructured and hard-to-follow code. 'exit' is a function call that terminates the entire program, rather than just returning from a function. 'continue' is used within loop structures to skip the remaining iterations and continue with the next iteration of the loop, which is not related to returning from a function. Understanding the function of these keywords is essential in programming to ensure clear and efficient code execution.