Answer:
The correct answer is B. Retrieval cues
Step-by-step explanation:
To explain the answer first we have to understand what retrieval is: it's the process of accesing information previously stored in our long term memory.
Now, with that clarified, retrieval cues are stimuli that helps you retrieve that long term memory that is stored, it brings the memory into your conscious awereness, in this example, when giving Peter two possibilites the stimuli was the differencial factor responsible for Peter remembering what he couldn't remember when no possibilities where given, therefore this example most clearly demonstrates the value of Retrieval cues.