Which scale is typically used for Planning Poker?
XS, S, M, L, XL
2, 4, 6, 8, 10
1, 2, 3, 4, 5, 8, 13, 20
less than 1 hour, 1 to 4 hours, 4 to 8 hours, 8 to 24 hours, more than 24 hours