Stoichiometric Amounts of Nitrogen Gas and Hydrogen Gas React in a Calorimeter

Stoichiometric amounts of nitrogen gas and hydrogen gas react in a calorimeter to produce 5.00 g of ammonia gas. The calorimeter temperature rises 0.42 $\degree$ C. The calorimeter and water have a combined heat capacity of 32.16 kJ/K. Calculate the heat of formation of ammonia, $\Delta$ H_f $\degree$ , in kJ/mol. The formation reaction for ammonia is:

A) -46 kJ/mol
B) -13.5 kJ/mol
C) -3.97 kJ/mol
D) 3.97 kJ/mol
E) 13.5 kJ/mol