The velocity distribution in a turbulent boundary layeris given by $$\frac{u}{v} = \left(\frac{y}{\delta}\right)^{\frac{1}{7}}$$. What is the displacement thickness $$\delta^*$$

A

$$\delta$$

B

$$\frac{\delta}{7}$$

C

$$\frac{7 \delta}{8}$$

D

$$\frac{\delta}{8}$$