There is more than one correct answer

$8.$ The following descriptions are Common Revenue Models $($CRM$).$ Please choose one of some "incorrect" description$($s$)$ provided below.

A$.$ Expenses that include both variable costs and fixed costs can be regarded as CRM$.$

B$.$ Customers pay a fixed price per unit in exchange for a product or service.

C$.$ Revenues come from selling one or more products or services to generate revenues from other products or services.

D$.$ Customers pay a one$-$time licensing fee to be able to use or resell the product or service.

E$.$ Sales commissions are expenses that vary directly and proportionately with