So I pretty much need some help finding the average for this equation

z(t)=4tsin(t^2) [0, π^1/2]

The possible answers are:

A. 8/π

B. 8/π^1/2

C. 4/π

D. 4/π^1/2

E. none

I used the general average equation and attempted to replace t^2 with u and all that, but it got pretty confusing. Any help is appreciated.