$1.$ When charges to external users are a principal revenue source of an activity, the use of an Enterprise Fund is required by generally accepted accounting principles in each of the following situations except

A$.$ When user fees are charged for the majority of the activity$$s operations.

B$.$ When an activity is financed with debt that is secured solely by the pledge of revenues.

C$.$ When laws and regulations require that the activity's costs be recovered with fees and charges.

D$.$ When pricing policies of the activity establish fees and charges are designed for cost recovery