In which of the following equilibrium K_C and K_ P are not equal ?

Key Idea The reaction for which the number of moles of gaseous products $\left(n_{\mathrm{p}}\right.$ ) is not equal to the number of moles of gaseous reactants \left(\mathbf{n}_{\mathrm{R}}\right)$, has different value of$\mathrm{K}_{\mathrm{c}} and \mathrm{K}_{\mathrm{p}}$. (a)$\boldsymbol{n}_{\mathrm{P}}=\mathbf{n}_{\mathrm{R}}=2$, thus,$\mathrm{K}_{\mathrm{p}}=\mathrm{K}_{\mathrm{c}}$(b)$\mathrm{n}_{\mathrm{P}}=\mathrm{n}_{\mathrm{R}}=2$, thus,$K_{\mathrm{p}}=\mathrm{K}_{\mathrm{c}}$(c)$\mathrm{n}_{\mathrm{P}}=\mathrm{n}_{\mathrm{R}}=2$, thus,$\mathrm{K}_{\mathrm{p}}=\mathrm{K}_{\mathrm{c}}$(d)$n_p=2, n_R=1$, thus,$K_p \neq K_c