Final answer:
To undo the staging of changes in Git, the command 'git reset HEAD' is used. It will unstage the changes without discarding them, allowing for adjustments before a final commit.
Step-by-step explanation:
To undo your staging of changes in Git, you can use the command git reset HEAD. This command will unstage any changes you have added to the staging area and bring them back to your working directory without discarding the actual changes to the files. This command is helpful when you've accidentally staged files you didn't mean to, or if you want to selectively stage certain parts of your changes.
Other options like git commit --amend are used to modify the last commit, git revert HEAD is for creating a new commit that undoes the changes introduced by the last commit, and git checkout is used for switching branches or restoring working tree files. Therefore, the answer to the question How do you undo your staging of changes in Git? is A. git reset HEAD.