Save lecture on cassette and copy to CD

I used Audacity to transfer my cassette lecture into my computer. I want to now burn it to a CD. I have opened the Export selection and looked at the " save as type" , but I do not know which file to save my selection as. I want the CD to play in my car. Which file do I use.
Townfryers

see this tutorial from the manual: http://manual.audacityteam.org/o/man/burning_music_files_to_a_cd.html

WC