Final answer:
The correct answer is d. None of the above.
Step-by-step explanation:
The correct answer is d. None of the above. Out of the given options, mystery shopping, using hidden cameras, standing next to a store display, analyzing scanner data, and surveying shoppers are all observation methods of collecting data. However, none of the options provided in the question are observation methods. It is important to note that observation methods involve directly observing and recording data without manipulating the environment or asking questions to the subjects.