probability theory and mathematical statistics

A set of milk chocolate M&Ms hes 3 red pieces, 5 blue pieces and 7 yellow pieces. Two pieces were taken one by one with replacement, If we enumerate all pieces 1 through 15 what is the best way to represent a selection of pieces? Select one. a. As an arrangement w = (21. Z2). Z, = 1. 2. .... 15. 21 # 22 Oh As an arrangement w = (21, 22), 2 = 1, 2, C. As a combination w = (21. Z2), 2; = 1. 2. .... 15. 21572 O d. As a combination w = (21, 22], 2, = 1, 2, ..., 15, 21 # 22