AP-Chemistry question 6 of 11?

The heat units are wrong: it has to be some amount of heat per unit quantity, and for this problem we'll ume moles. There is enough water to permit one to suppose that the lime is the limiting reagent, and with the MW of lime being 40+16 = 56, we have about 0.12 moles of lime, which, times 64.8 kJ, gives about eight kJ in this case. Hence, answer B.