A quarter wave monopole antennais situated above a perfectly conducting ground plane.It is driven by a 50V source at 500MHz through an internal impedance of 63.5Ω . The average powerradiated by the antennais

A

39.37 W/m$$^2$$

B

4.56 W/m$$^2$$

C

68.49 W/m$$^2$$

D

45.6 W/m$$^2$$