The DC output power across a load of R ohms in a,half wave rectifier with a current flowing of peak value $$ I_m $$, is

A

$$\frac{(I_m^2R)}{\pi}$$

B

$$\left(\frac{I_m}{\pi}\right)^2 R$$

C

$$\frac{(I_m^2R)}{2 \pi}$$

D

$$\left(\frac{I_m}{2 \pi}\right)^2 R$$