a
The ratio of electric and magnetic field is given by,

\(\frac{E}{B}=\frac{\frac{K Q}{r^{2}}}{\frac{\mu_{0}}{4 \pi}\left(\frac{q V}{r^{2}}\right)}\)

\(=\frac{K Q 4 \pi}{\mu_{0} q V}\)

\(=\frac{1}{4 \pi \varepsilon_{0}}\left(\frac{4 \pi}{\mu_{0}}\right)\)

\(=\frac{C^{2}}{V}\)    \(....(I)\)

Substitute \(3 \times 10^{8}\) for \(C\) and \(4.5 \times 10^{5}\) for \(V\) in equation \(( I )\).

\(\frac{E}{B}=\frac{3 \times 10^{8}}{4.5 \times 10^{5}}\)

\(=2 \times 10^{11}\)