lf the average of s mumbers is $$r^{4}$$ and the average of r numbers is $$s^{4}$$, then find the average of all r + s numbers?

A

$$rs\left(r^{2} + s^{2} - rs\right)$$

B

rs

C

$$r^{2} + s^{2}$$

D

$$rs\left(r^{2} + s^{2}\right)$$