Which Statement by the Nurse Shows Understanding of the Rand

Which statement by the nurse shows understanding of the Rand Health Insurance Experiment?

A) "When consumers were required to pay 25% co-payment,there was a considerable decline in the use of health care services."
B) "There was an increase in the use of health care services when consumers were required to make a co-payment."
C) "If the health care cost is being paid by insurance companies,the consumer is not concerned about the cost."
D) "The implementation of the Oregon Health Policy for reimbursement of the cost of health care services led to the Rand Health Insurance Experiment."