If a man travels at $$\frac{1}{x}$$ km/h on a journey and returns at $$\frac{1}{x^{2}}$$ kh/h, then his speed for the journey is:

A

$$\frac{x + 1}{x^{2}}$$

B

$$\frac{1}{ x + x^{2}}$$

C

$$\frac{2}{x + x^{2}}$$

D

$$\frac{2x^{2}}{ x + 1}$$