, This person unlock, free to dial the last number just to unlock the probability is A.1 / 10B.1 / 8C.1 / 6D.1 / 5 Detailed
Free to dial the last number just to unlock the probability is one-fifth, so the election D
Because the last digit there are five possibilities, so just to unlock the possibility of one-fifth, choose D.
Because only forgot the last one, so he dialed the two after the third when there are five options, respectively, 1.3.5.7.9, so free to dial the last number just to unlock the probability is a fifth One, so choose D