Final answer:
The correct configuration for specifying a merge with the ref in version control systems is GitMerge, which uses the git merge command in Git to combine branch changes.
Step-by-step explanation:
The configuration that specifies to merge with the ref is related to version control systems. GitMerge is the correct answer. Git is a distributed version control system that allows multiple developers to work on the same code base without interfering with each other. Using the git merge command, you can combine the changes from one branch into another, which could be the master branch or any other branch in the project. Each of the other options, namely SVNCommit, HgUpdate, and CVSCombine, relate to different version control systems like Subversion, Mercurial, and CVS, respectively, and they do not specifically refer to a merge command synonymous with Git.