As 3 dice are thrown so there are 6×6×6 = 216 possibilities.

Let E denote the event of getting a total score of 5.

{(1,1,3),(1,2,2)}

As (1,1,3) can be arranged in

and (1,2,2) can be arranged in

∴ n(E) = 6

Hence,

P(E) = 6/36 = 1/6

As our answer matches only with option (b)

∴ Option (b) is the only correct choice.