No one else was undefeated. Would BYU have won the NC under Steve Young with a 12-0 year?
Top three were
Miami
Nebraska
Auburn
Miami (11-1) won the NC by beating Nebraska (11-1) in the Orange Bowl.
Only ranked teams BYU beat were UCLA and Air Force, which ended up at 17 and 22. Stronger year than 84, but stronger competitors for the NC.