Simon wants to earn as many points as possible in one turn in a game. Two number cubes whose sides are numbered 1 through 6 are rolled. He is given two options for the manner in which points are awarded in the turn. OPTION A: If the sum of the rolls is a prime number, Simon receives 15 points. OPTION B: If the sum of the rolls is a multiple of 3, Simon receives 12 points. Which statement best explains the option he should choose?