Final answer:
B. It is the maximum rate of deviation from a prescribed control that an auditor is willing to accept. The expected rate of deviation is the maximum rate of deviation from a prescribed control that an auditor is willing to accept.
Step-by-step explanation:
The expected rate of deviation refers to the rate at which the auditor expects controls to not function as planned. It is the maximum rate of deviation from a prescribed control that an auditor is willing to accept. This allows for a margin of error and recognizes that not all controls will perform perfectly.