The R-L circuit of the figure is fed from a constant magnitude variable frequency sinusoidal voltage source v_in. At 100 Hz, the R and L element each has a voltage drop $$U_{rms}$$. If the frequency of the source is changed to 50 Hz, then new voltage drop across R is:-

A

$$\sqrt{\frac{5}{8}}U_{rms}$$

B

$$\sqrt{\frac{2}{3}}U_{rms}$$

C

$$\sqrt{\frac{8}{5}}U_{rms}$$

D

$$\sqrt{\frac{3}{2}}U_{rms}$$