What allows different people to work on various program functions simultaneously?

The reason modular programming through methods enables different people to work on various program functions simultaneously is that it supports dividing a program into smaller, manageable sections, or modules. Each method can encapsulate specific functionality, allowing different team members to develop, test, and debug their assigned methods independently.

This division of labor not only promotes collaboration but also enhances code organization, making it easier to maintain and understand. With modular programming, responsibilities are clearly defined, leading to more efficient teamwork and quicker integration of individual components. As a result, different developers can focus on distinct aspects of a program without stepping on each other's toes, ultimately improving productivity and the speed of development.

In contrast, single-threaded execution would limit the program to running one task at a time, making collaboration on various functions simultaneously impossible. Using global variables can lead to complications, as changes made by one programmer could unintentionally affect another's work, reducing collaboration efficiency. Implementing fewer methods tends to lead to larger, more complicated code sections, hindering the potential for effective parallel work.