When a Client Uses a Service Center for Processing Transactions

When a client uses a service center for processing transactions,

A) the auditor can assume that the controls are adequate because it is an independent enterprise.
B) auditing standards require the auditor to test the service center's controls if the service center application involves processing significant financial data.
C) and the user auditor decides to rely on the service auditor's report,the user audit must make reference to the report of the service auditor in the opinion on the user organization's financial statements.
D) none of the above