Consider the reflection and refraction of a plane electromagnetic wave at the interface of two linear isotropic media, assuming the interface is an infinitely large smooth plane. Provide the expression for the reflectance. Please define the notations for the relevant physical quantities as needed.

Options:
A. $$
\left( \frac{-\sqrt{\varepsilon_{1} / \mu_{1}} \operatorname{c o s} \theta_{t}+\sqrt{\varepsilon_{2} / \mu_{2}} \operatorname{c o s} \theta_{i}} {\sqrt{\varepsilon_{1} / \mu_{1}} \operatorname{c o s} \theta_{t}+\sqrt{\varepsilon_{2} / \mu_{2}} \operatorname{c o s} \theta_{i}} \right)^{2}
$$
B. $$
\left( \frac{-\sqrt{\mu_{1} / \varepsilon_{1}} \operatorname{s i n} \theta_{t}+\sqrt{\mu_{2} / \varepsilon_{2}} \operatorname{s i n} \theta_{i}} {\sqrt{\mu_{1} / \varepsilon_{1}} \operatorname{s i n} \theta_{t}+\sqrt{\mu_{2} / \varepsilon_{2}} \operatorname{s i n} \theta_{i}} \right)^{2}
$$
C. $$
\left( \frac{-\sqrt{\varepsilon_{2} / \mu_{1}} \operatorname{s i n} \theta_{i}+\sqrt{\varepsilon_{1} / \mu_{2}} \operatorname{s i n} \theta_{t}} {\sqrt{\varepsilon_{2} / \mu_{1}} \operatorname{s i n} \theta_{i}+\sqrt{\varepsilon_{1} / \mu_{2}} \operatorname{s i n} \theta_{t}} \right)^{2}
$$
D. $$
\left( \frac{\sqrt{\varepsilon_{2} / \mu_{1}} \operatorname{c o s} \theta_{i}+\sqrt{\varepsilon_{1} / \mu_{2}} \operatorname{s i n} \theta_{t}} {\sqrt{\varepsilon_{2} / \mu_{1}} \operatorname{c o s} \theta_{i}-\sqrt{\varepsilon_{1} / \mu_{2}} \operatorname{s i n} \theta_{t}} \right)^{2}
$$
E. $$
\left( \frac{-\sqrt{\mu_{2} / \varepsilon_{2}} \operatorname{s i n} \theta_{i}+\sqrt{\mu_{1} / \varepsilon_{1}} \operatorname{c o s} \theta_{t}} {\sqrt{\mu_{2} / \varepsilon_{2}} \operatorname{s i n} \theta_{i}+\sqrt{\mu_{1} / \varepsilon_{1}} \operatorname{c o s} \theta_{t}} \right)^{2}
$$
F. $$
\left( \frac{-\sqrt{\varepsilon_{1} / \mu_{1}} \operatorname{s i n} \theta_{i}+\sqrt{\varepsilon_{2} / \mu_{2}} \operatorname{s i n} \theta_{t}} {\sqrt{\varepsilon_{1} / \mu_{1}} \operatorname{s i n} \theta_{i}+\sqrt{\varepsilon_{2} / \mu_{2}} \operatorname{s i n} \theta_{t}} \right)^{2}
$$
G. $$
\left( \frac{\sqrt{\varepsilon_{1} / \mu_{2}} \operatorname{c o s} \theta_{i} - \sqrt{\varepsilon_{2} / \mu_{1}} \operatorname{c o s} \theta_{t}} {\sqrt{\varepsilon_{1} / \mu_{2}} \operatorname{c o s} \theta_{i} + \sqrt{\varepsilon_{2} / \mu_{1}} \operatorname{c o s} \theta_{t}} \right)^{2}
$$
H. $$
\left( \frac{\sqrt{\varepsilon_{2} / \mu_{2}} \operatorname{c o s} \theta_{i} - \sqrt{\varepsilon_{1} / \mu_{1}} \operatorname{c o s} \theta_{t}} {\sqrt{\varepsilon_{2} / \mu_{2}} \operatorname{c o s} \theta_{i} + \sqrt{\varepsilon_{1} / \mu_{1}} \operatorname{c o s} \theta_{t}} \right)^{2}
$$
I. $$
\left( \frac{-\sqrt{\varepsilon_{2} / \mu_{1}} \operatorname{s i n} \theta_{t} + \sqrt{\varepsilon_{1} / \mu_{2}} \operatorname{c o s} \theta_{i}} {\sqrt{\varepsilon_{2} / \mu_{1}} \operatorname{s i n} \theta_{t} + \sqrt{\varepsilon_{1} / \mu_{2}} \operatorname{c o s} \theta_{i}} \right)^{2}
$$
J. $$
\left( \frac{-\sqrt{\varepsilon_{1} / \mu_{2}} \operatorname{c o s} \theta_{t} + \sqrt{\varepsilon_{2} / \mu_{1}} \operatorname{s i n} \theta_{i}} {\sqrt{\varepsilon_{1} / \mu_{2}} \operatorname{c o s} \theta_{t} + \sqrt{\varepsilon_{2} / \mu_{1}} \operatorname{s i n} \theta_{i}} \right)^{2}
$$
Answer: A