Hello!
The reaction that took place was 
B) exothermic. The equation for the ΔH is 

To know if this reaction is 
exothermic or 
endothermic we will need to look at the 
sign of the 
ΔH. If it is 
positive, it means that enthalpy of the products is 
higher than the enthalpy of the reagents and the reaction is 
endothermic.
If the sign is negative, it means that the enthalpy of the products is 
lower than the enthalpy of the reagents and the reaction is 
exothermic. In this case, the sign is negative, so the reaction is exothermic.
Have a nice day!