Final answer:
The authorization for insurance payment to be made directly to the physician is known as an assignment of benefits. It is a common practice in health insurance, differing from the fee-for-service or HMO models of payment.
Step-by-step explanation:
The term used for the authorization to an insurance company to make payment directly to the physician is C. assignment of benefits. This term refers to a formal agreement where a patient allows their health insurance payments to be made directly to a medical service provider.
This contrasts with systems like fee-for-service or health maintenance organizations (HMOs). In the fee-for-service system, providers are remunerated per service rendered, whereas HMOs receive a fixed amount per enrolled individual, not based on the number of services.