As Part of a Preliminary Survey of the Purchasing Function

As part of a preliminary survey of the purchasing function, an internal auditor reads the department's policies and procedures manual and concludes that the manual describes the processing steps clearly and contains an appropriate internal control design. The next engagement objective is to evaluate the operating effectiveness of internal controls. Which procedure would fulfill this objective most effectively?

A) Perform a design test.
B) Perform a compliance test.
C) Perform a systems test.
D) Perform an efficiency test.