what is the best answer and why?

Which of the distributions below has the larger standard deviation? . .. Distribution A ...... .... 90 100 80 Distribution B 30 40 50 70 20 A) Distribution A B) Distribution B C) The standard deviations are equal since the means are equal. D) The standard deviations are equal since the ranges are equal. E) The standard deviations are equal since both distributions are symmetric