I want to know the answer to the following question:
What audio playback options were available if an AC-3 output was not present?
All the background I'm provided with is that "If either the player did not support digital audio tracks (common in older players), or the disc did not include digital audio tracks at all (uncommon for a disc which is mastered with an AC-3 track), the only remaining option was to fall back to a monophonic presentation of the left analog audio track.". Is that enough to answer the question?
Answer: no