Understanding the 'git merge --no-ff' Command

The correct answer to the quiz question is that the git merge --no-ff command creates a merge commit even if a fast-forward merge is possible. This is a crucial aspect of Git, a distributed version control system used for tracking changes in any set of files, usually used for coordinating work among programmers collaboratively developing source code during software development.

Git has different types of merge strategies, and the fast-forward merge is one common strategy. In a fast-forward merge, if the branch you are merging into hasn't had any new commits since you branched off, Git will just move the branch pointer to point at the latest commit. So, in this case, it "fast-forwards".

However, the --no-ff option changes this behavior. When we use git merge --no-ff, Git will always create a new commit object, even if a fast-forward merge is possible. It does this to preserve information about the historical existence of a feature branch and groups together all commits that together added a feature.

Let's take a practical example to understand this. Suppose you are working on a feature in its separate branch, and during your work, you made several commits. If you merge this branch using the fast-forward approach, Git would merely update the pointers, and your commit history would be linear. This approach may lead to losing the context that these commits together constitute a feature as there is no record of this branch in history.

Therefore, by using git merge --no-ff, you ensure that your Git history clearly communicates the group of commits as a chunk of work, which can be very useful for code reviews and rolling back changes. An additional benefit is that it provides a clear structure that shows when and where a branch started and merged.

In summary, best practices in project management argue for keeping a clean and decipherable history of your projects. Therefore, using git merge --no-ff assures such cleanliness by creating a new commit that reflects the merger of a branch, even if a fast-forward merge could be performed. In this way, the complete history of the project’s development remains intact and understandable when we view our Git log in the future.