Match the Definition with the Quantity It Is Describing $\Delta_{c} H^{\circ}$

Match the definition with the quantity it is describing.
- $\Delta_{c} H^{\circ}$

A) Energy required to melt one mol of a pure substance at its melting point, T_m, at 1 bar pressure
B) Energy required to vaporize one mole of a pure liquid at its boiling point, T_b, at 1 bar pressure
C) Enthalpy change at 298 K when 1 mol of a compound is formed under standard conditions from its constituent elements in their standard states
D) Enthalpy change when 1 mol of a substance reacts completely with oxygen gas at 1 bar pressure