This is aptitude question, actually! (concept of power cycle will be helpful)
a) (0,1,4,9,6,5,6,9,4,1,0) repeated [Not including 2,3,7,8] (loss of 4)
b) (0,1,8,7,4,5,6,3,2,9) repeated [Includes everyone]
c) (0,1,4,9,6,5,6,9,4,1,0) repeated [Not including 2,3,7,8] (loss of 4)
d) (0,2,4,6,8) repeated [Not inluding any odd nos.](loss of 5)
Answer is (B)