The easiest solution is to create a choice custom field, render it as dropdown (from Administration > Settings > Advanced > News > Controls > Views > NewsBackendEdit > Sections > CustomFieldSection > Fields > YourField and set RenderChoiceAs to "DropDown").
Then you need to modify List and SingleItem template to render it.
Here is a video
of the set-up.
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items