This question is not complete ,the options will be:
A - 2
3 B - 1.5 C- 15 % D- 0.7
The right option is B- 1.5
The number which can not represent a probability is B.1.5 for it is more than 1.So it indicates probability of any incident occurs between 0 to 1. As 1.5>1, thus can not represent probability.