The correct option is D 60
Multiples of 4 = 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60.
Multiples of 6 = 6, 12, 18, 24, 30, 36, 42, 48, 54, 60.
Multiples of 5 = 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60.
Common multiple is 60 which is also smallest.