The correct answer is CodeCommit because it is designed to provide a secure, highly scalable, and private Git repository hosting service, which is essential for version control in code development. CodeBuild is a service for compiling source code and running tests, so it doesn't provide version control hosting. Cloud9 is an IDE that allows for editing and debugging code, and therefore doesn't serve as a hosting service for repositories. CodeStar is a service to manage software development activities, but not specifically for hosting version-controlled repositories.