Kilocalorie is a unit of measuring the amount of energy of a reaction, but this is not the only unit, we can also have Joules as a unit, and the conversion is:
1 Kcal = 4184 Joules
Therefore if we have 3.25 Kcal, we will have:
3.25 * 4184 = 13600 Joules of energy, therefore letter D