From the Luria- Delbruck Fluctuation Test,when Would Mutations Arise in Yeast

From the Luria- Delbruck fluctuation test,when would mutations arise in yeast cells to allow for survival in the presence of toxic levels of hydrogen peroxide?

A) Mutations are adaptive and would have formed prior to being exposed to hydrogen peroxide.
B) Mutations are adaptive and would have appeared immediately in response to the hydrogen peroxide.
C) Mutations are random and would have appeared prior to being exposed to hydrogen peroxide.
D) Mutations are random but would not have formed until after the hydrogen peroxide was introduced.
E) Mutations are adaptive and would have appeared after most of the cells died in the presence of hydrogen peroxide.