For maximum discharge, ratio of the pressure at the exit and at inlet of nozzle $$\left(\frac{P_2}{P_1}\right)$$ is equal to:

A

$$\left[\frac{2}{(n + 1)}\right]^{\frac{(n + 1)}{n}}$$

B

$$\left[\frac{2}{(n + 1)}\right]^{\frac{n}{(n - 1)}}$$

C

$$\left[\frac{2}{(n + 1)}\right]^{\frac{(n - 1)}{n}}$$

D

$$\left[\frac{2}{(n + 1)}\right]^{\frac{n}{(n + 1)}}$$