To integrate changes from an existing branch named 'feat00304' into a single commit with the current working primary branch 'prodapp411926287', the git merge --squash command must be used. This command squashes all commits from the feature branch into a single commit before merging. A: git rebase --merge feat00304 - Incorrect. This command does not perform a squash merge. B. git merge --squash feat00304 - Correct. This command squashes all commits from 'feat00304' into a single commit and then merges it. C. git push --rebase feat00304 - Incorrect. This command is used for pushing changes and rebasing, not for squashing commits. D. git checkout --squash feat00304 - Incorrect. This command is invalid. References: * Git Merge Squash