A red LED emits light at $0.1$ watt uniformly around it. The amplitude of the electric field of the light at a distance of $1m$ from the diode is

Question

$\begin{array}{1 1} 5.48\;V/m \\ 7.75 \;V/m \\ 1.75\;V/m \\ 2.45\;V/m \end{array} $