The correct option is A greater than −57.33kJmol−1
The enthalpy of hydration of Mg2+ ion is very high. Due to this, the absolute enthalpy of neutralization of the reaction is greater than −57.33KJmol−1. The △H for the above reaction is found to be −146KJ which states that the enthalpy of neutralization of H+ is −73KJ/mol which is greater than the enthalpy of neutralization i.e. 57.33KJ/mol.