A "mystery shopper" is an anonymous person whose purpose is to enter a store and record how he or she was treated by the staff. The mystery shopper then reports findings to the management. Which of the following best describes a mystery shopper?

A. covert and structured>>>>>>>

B. covert and unstructured

C. overt and structured

D. overt and unstructured

I know its covert, but dont know whether its structured or unstructured.