The essential difference between an AC generator and a DC generator is that:(a) AC generator has an electromagnet while a DC generator haspermanent magnet.(b) DC generator will generate a higher voltage.(c) AC generator will generate a higher voltage.(d) AC generator has slip rings while the DC generator has a commutator.A. AC generator has an electromagnet while a DC generator has permanent magnetB. DC generator will generate a higher voltage.C. AC generator will generate a higher voltage.D. AC generator has slip rings while the DC generator has a commutator