Which of the following is equivalent to S = {spring, summer, autumn, winter}?
(you may select more than one)

{x | x = states in the United States}

{x|x is a season}

{x|x = planets in our solar system}

{x | x = former Presidents of the United States}

{x|x ≥ 1 and x < 5}

{x | x = sides of a standard dice}