Select the option in which the numbers are NOT related in the same way as are the numbers of the following set. (7, 21, 49)

(9, 27, 72) (6, 18, 36) (5, 15, 25) (8, 24, 64)

(9, 27, 72)

(7, 21, 49) The logic followed here is : As 7 × 3 = 21 and 7 × 7 = 49 Checking in all options (9, 27, 72) ⇒ 9 × 3 = 27 and 9 × 9 = 81≠72 (6, 18, 36) ⇒ 6 × 3 = 18 and 6 × 6 = 36 (5, 15, 25) ⇒ 5 × 3 = 15 and 5 × 5 = 25 (8, 24, 64) ⇒ 8 × 3 = 21 and 8 × 8 = 64