A question on the 700mb/80min. max. amount of data on cd-r's

[hamface]

Hi, I'm brand new to this whole burning cd's and cd-r technology, so I know this question may sound pretty lame but:

When recording actual music files (WMA) to a cd-r is the restriction

a.) 700mb worth of music
b.)80 minutes of music
c.)whichever fills up first?

Thanks a lot, this question has been bugging me for awhile!!