The correct option is Manually one by one, with automation rules, or by importing many items together.

GitHub Projects lets you add issues and pull requests directly from the project interface when you want to curate items individually. You can also configure built in project automation so that items are added automatically based on rules like repository, filters, or events which keeps your board up to date without constant manual work. When you need to seed or update a board with many items at once you can bulk add from search or import via CSV to bring in a large set efficiently.

The statement Only by using the GitHub CLI is incorrect because the web interface supports manual addition, built in automation can auto add items, and bulk import is available.

The statement Only through automated project workflows such as GitHub Actions is incorrect because you can add items manually in the project and you can also import many at once without relying on Actions.

The statement Only by adding one item at a time manually is incorrect because you can use automation to add items automatically and you can perform bulk imports when needed.

Full AWS Practitioner Certification Question