Hydrazine, N₂H₄, Is a Liquid Used as a Rocket Fuel $\ell$

Hydrazine, N₂H₄, is a liquid used as a rocket fuel. It reacts with oxygen to yield nitrogen gas and water.
N₂H₄( $\ell$ ) + O₂(g) ? N₂(g) + 2 H₂O( $\ell$ )
The reaction of 6.50 g N₂H₄ evolves 126.2 kJ of heat. Calculate the enthalpy change per mole of hydrazine combusted.

A) -19.4 kJ/mol
B) -25.6 kJ/mol
C) -126 kJ/mol
D) -622 kJ/mol
E) -820. kJ/mol