At constant temperature, the equilibrium constant $\left({\mathrm{K}}_{\mathrm{P}}\right)$ for the decomposition reaction

${\mathrm{N}}_2{\mathrm{O}}_4 \rightleftharpoons 2{\mathrm{NO}}_2$ is expressed by ${\mathrm{K}}_{\mathrm{P}}= \frac{\left(4{\mathrm{x}}^2\mathrm{P}\right)}{\left(1-{\mathrm{x}}^2\right)},$  where P = pressure, x = extent of decomposition. Which one of the following statements is true ?

At constant temperature, the equilibrium constant (K_p​) for the decomposition reaction,
N₂​O₄​⇌2NO2​
is expressed by:
K_p​=$\frac{4{\mathrm{x}}^2\mathrm{P}}{\left(1-{\mathrm{x}}^2\right)}$​
Where, P=pressure, x= extent of decomposition. The following statement is true.
K_p​ remains constant with change in P and x
The value of the equilibrium constant depends on temperature. It is not affected by changes in concentration, pressure, extent of dissociation or presence of catalyst.