What Is the Equilibrium Constant Expression for the Reaction Shown $\frac { [ \mathrm { MgO } ] \left[ \mathrm { CO } _ { 2 } \right] } { \left[ \mathrm { MgCO } _ { 3 } \right] }$

What is the equilibrium constant expression for the reaction shown below?

A) K_eq = $\frac { [ \mathrm { MgO } ] \left[ \mathrm { CO } _ { 2 } \right] } { \left[ \mathrm { MgCO } _ { 3 } \right] }$
B) K_eq = $\frac { \left[ \mathrm { MgCO } _ { 3 } \right] } { [ \mathrm { MgO } ] \left[ \mathrm { CO } _ { 2 } \right] }$
C) K_eq = $\frac { [ \mathrm { MgO } ] + \left[ \mathrm { CO } _ { 2 } \right] } { \left[ \mathrm { MgCO } _ { 3 } \right] }$
D) K_eq = [MgO][CO₂]
E) K_eq = [CO₂]