Pick out the exothermic reaction out of the following:
(A) C + H2O = CO + H2
(B) CaC2 + H2O = Ca(OH)2 + C2H2
(C) MgCO3 = MgO + CO2
(D) All (A), (B) and (C)
(A) C + H2O = CO + H2
(B) CaC2 + H2O = Ca(OH)2 + C2H2
(C) MgCO3 = MgO + CO2
(D) All (A), (B) and (C)