What is the equilibrium constant expression, \({K_{\text{c}}}\), for the following reaction?

\[{{\text{N}}_{\text{2}}}{{\text{O}}_{\text{4}}}{\text{(g)}} \rightleftharpoons {\text{2N}}{{\text{O}}_{\text{2}}}{\text{(g)}}\]

A.     \({K_{\text{c}}} = \frac{{[{\text{N}}{{\text{O}}_2}]}}{{[{{\text{N}}_2}{{\text{O}}_4}]}}\)

B.    \({K_{\text{c}}} = \frac{{{{[{\text{N}}{{\text{O}}_2}]}^2}}}{{[{{\text{N}}_2}{{\text{O}}_4}]}}\)

C.    \({K_{\text{c}}} = \frac{{[{\text{N}}{{\text{O}}_2}]}}{{{{[{{\text{N}}_2}{{\text{O}}_4}]}^2}}}\)

D.    \({K_{\text{c}}} = [{\text{N}}{{\text{O}}_2}]{[{{\text{N}}_2}{{\text{O}}_4}]^2}\)

B