So... Can you please tell me which approach is valid?

I have a set of 3 repeated measurements for 2 groups, I want to test for differences between measurements and for differences between groups

First measurement is normally distributed, the others are not...

What is the right way to test for differences between measurements and differences between groups?

a) do the Friedman test for each group, and then test each measurement between groups (first Student's t, and then Mann Whitney)

b) do the RM-ANOVA with existing data

c) do the Box-Cox transform and then the RM-ANOVA

Thanks