After Testing Internal Controls,how Will the Auditor Determine Whether the Internal

After testing internal controls,how will the auditor determine whether the internal control is effective?

A) The decision is made based on whether the controls are in place.
B) The decision is made based on the number of deviations the auditor finds in the internal controls.
C) The decision is made based on whether the controls are operating effectively.
D) The decision is made based on whether internal controls effectively prevent misstatements or detect misstatements in the financial statements.