What is the standard enthalpy of formation of MgCO3( s )?

What is the standard enthalpy of formation of MgCO3(s)?

                                      MgO(s) + CO2(g)  → MgCO3(s);          ΔH° = -100.7 kJ

 SubstanceΔH°f (kJ/mol)

MgO(s)-601.6

CO2(g)-393.5

A. 107.4 kJ

B. -308.8 kJ

C. -894.4 kJ

D. -1095.8 kJ

E. 894.4 kJ