Answer:
In this situation, the hint acted as a(n) d. retrieval clue.
Step-by-step explanation:
A retrieval clue is a prompt or stimulus that helps us retrieve a memory. It is a type of extra information concerning a person, a place, or a situation, for instance, which allows us to remember that person, place, or situation more easily. Imagine you meet someone new at a friend's house, where they are having a barbecue. Days later your friend asks you if you remember that person, but you don't. Then he gives you details, such as "He is the one who talked to you while you were filling your plate." Because of that clue, you are able to remember that person's face and name. That clue is a retrieval clue.
In the situation in the passage, you have two types of information about Grover Cleveland. First, you know he was a president. Second, you know there is a city named after him. Those pieces of information function as a retrieval clue, allowing you to remember his name.