What is the main purpose of using a source control tool in software development?

Using a source control tool in software development primarily serves the function of managing changes to source code over time. This allows developers to track revisions, understand the history of changes, and collaborate more effectively with team members. Source control systems maintain a complete history of all modifications, which includes the ability to revert to previous versions if necessary, facilitating experimentation without the risk of losing past work.

Additionally, source control tools support branching and merging, allowing multiple developers to work on different features simultaneously without conflicts. This organized approach not only enhances collaboration but also improves overall code quality by enabling code reviews and maintaining stable codebases.

While improving graphics, enhancing execution speed, and compiling code are essential aspects of software development, they are not the primary functions of source control tools. Their focus is specifically on code management, making option B the correct answer.