About `6%` of the power of a 100 W light bulb is converted ot visible radiation. The average intensity of visible radiation at a distance of 8 m is (Assume that the radiation is emitted isotropically and neglect reflection.)
A. `3.5xx10^(-3)"W m"^(-2)`
B. `5.1xx10^(-3)"W m"^(-2)`
C. `7.2xx10^(-3)"W m"^(-2)`
D. `2.3xx10^(-3)"W m"^(-2)`