What is the primary function of comments in code?

The primary function of comments in code is to document and explain the code. Comments serve as an important communication tool between the programmer and anyone else who may read or work with the code in the future, including the original author. They help clarify the purpose of specific sections of code, describe why particular decisions were made, and provide insight into the intended functionality. This documentation enhances code readability and maintainability, making debugging and future modifications easier for everyone involved.

Options that suggest executing code faster, replacing complex logic, or increasing the size of the program do not align with the fundamental purpose of comments, which is solely to enhance understanding of the code rather than to change how the code functions or performs.