Which statement is accurate regarding cost control in countries other than the U$.$S$.?$

a$.$ If there are multiple payers, the terms of payment from each payer is much the same.

b$.$ Most hospitals and physicians collect revenues from many payers on many different terms.

c$.$ Each payer tries to negotiate better prices by threatening to take its business to other providers of care.

d$.$ Providers of care are encouraged to buy new equipment and expand their facilities to increase costs and revenues