Calculate the coefficient of variation and rank the five alternatives from the lowest risk to the highest risk by using the coefficient of variation.

a. 0.15 - 0.20 - 0.25 - 0.30 - 0.35
b. 0.25 - 0.30 - 0.20 - 0.15 - 0.35
c. 0.20 - 0.25 - 0.15 - 0.35 - 0.30
d. 0.35 - 0.30 - 0.25 - 0.20 - 0.15