Which one of the following is the use of function in python?

In Python, the primary use of functions is to create reusable pieces of programs.
Functions allow you to encapsulate a block of code that performs a specific task and give it a name, making it reusable throughout your program. By defining functions, you can break down complex tasks into smaller, more manageable units, which improves modularity and maintainability of your code. Functions can be called multiple times from different parts of your program, allowing you to avoid code duplication and write more efficient and organized code. Therefore, the correct usage of functions in Python is that they are reusable pieces of programs.