When calculating p.u. parameters in a power system, the rules of selecting basevalues are (a)The base value of the active power is chosen to be the same for all items

in the whole network and the base voltages must be in the ratio of the turns of transformers. (b)Both the base values of the active power and voltages are chosen to be the same for all items in the whole network. (c)Both the base values of the apparent power and voltages are chosen to be the same for all items in the whole network (d)The base value of the reactive power is chosen to be the same for all items in the whole network and the base voltages must be in the ratio of the turns of transformers. the turns of transformers.The base value of the apparent power is chosen to be the same for all items in the whole network and the base voltages must be in the ratio of the turns of transformers.(e)