Explanation/Reference:
Launches enables you to efficiently develop the content for a future release of one or more activated web pages.
A launch is created to allow you to make changes ready for future publication. After editing and updating your launch pages you promote them and activate the source pages.
Incorrect Answers:
D: With versioning, you can perform the following functions:
Create a version of an asset.

View what revision of the asset you are using.

Restore the asset to a previous version.

References: https://docs.adobe.com/docs/en/aem/6-0/author/site-page-features/launches.html