Hello Paul,
That question is shown only when you're setting up a listing.
Airbnb uses the answer to adjust some of the settings for the listing.
One setting it affects is preparation time in the "Availability" section on the calendar.
If you say "occasionally" when setting up the listing then I think may set preparation time to 2 days. If you say "all the time" it may set it to "none".
The post below describes some of the things that affect the smart pricing calculation.
From it, if you select "all the time" when setting up the listing, and get lots of bookings it could make a difference to the calculation over having selected "occasionally" and haveing days before and after a booking blocked.
How Smart Pricing Works
Steve.