Poll feature in a form

I am looking for a form, that allows me to capture all the requested information about the interviewee (Name, Email, …) as well as an option to pick an interview slot out of a list. Slots that have been taken need to be removed from the list. Is there a feature or workaround for that problem?

A dropdown-list doesn’t work and i am oursourcing that problem with a doodle List.