What metric is used to estimate with Planning Poker?

Choose one or more of the following:

• The Fibonacci sequence (1, 2, 3, 5, 8, 13, 21, 34, etc.)

Why this is the correct answer

Fibonacci sequence is one of the most used techniques in Planning Poker, but other are used as well, like: Scrum type deck, Sequential, T-shirt sized deck and Hours type.