Option week is an additional week of vacation that is paid as 40 hours instead of 45 hours. You have the option to schedule this vacation like a normal vacation week OR get paid out without taking the week off.
Option days are 8 hour days you schedule in advance. I'm fuzzy on the details exactly but it's something like 10 business days here. In my center they usually will schedule it with less notice no one has that day scheduled off. That's why I don't know the exact details. I'm in the Western conference.