You have been assigned to select a transformer to supply a peak power of 100 kW to a load that draws peak power only a very small percentage of the time and draws very little power the rest of the time. Two transformers, A and B, are both suitable. While both transformers have the same efficiency at peak load, most of the loss in A is due to core loss, and most of the loss in B is due to the resistances of the coils. From the standpoint of operating costs, which transformer is better? Why?