A plane electromagnetic wave of frequency ω is incident normally on an air-dielectric interface. The dielectric is linear, isotropic, non-magnetic and its refractive index is n. The reflectance (R) and transmittance (T) from the interface are

A. $$R = {\left( {\frac{{n - 1}}{{n + 1}}} \right)^2},\,T = \frac{{4n}}{{{{\left( {n + 1} \right)}^2}}}$$

B. $$R = - \left( {\frac{{n - 1}}{{n + 1}}} \right),\,T = \frac{2}{{{{\left( {n + 1} \right)}^2}}}$$

C. $$R = {\left( {\frac{{n - 1}}{{n + 1}}} \right)^3},\,T = \frac{{4{n^3}}}{{{{\left( {n + 1} \right)}^3}}}$$

D. $$R = \frac{{{{\left( {n - 1} \right)}^2}}}{{n + 1}},\,T = \frac{{4{n^2}}}{{{{\left( {n + 1} \right)}^2}}}$$

Answer: Option A