Which of the Following Is Incorrect Regarding Service Firms

Which of the following is incorrect regarding service firms?

A) Each client or account is equivalent to a process in a process costing firm.
B) The accounting system will track the time and resources spent serving a specific client or account.
C) Managers of service firms need cost information to price their services,to budget and control costs,and to determine the profitability of different types of clients.
D) The primary driver used to assign costs is billable hours.