According to the excerpt, the option that identifies an implicit meaning one could draw from it would be the second one: "Locke is unfamiliar with the term <em>idea</em>".
In the excerpt, Locke is not asking what Idea is nor is he being uncertain about the relationship between speculative and practical ideas. He seems to never heard it before and the exact meaning fades away.
That's why he asks what it represents and not its definition or for someone to repeat the explanation. He just needs an example to clarify the boundaries of the <em>idea's</em> meaning.
1. Aren't there a lot of quoted passages in your paragraph, Richard?
2. The students had sold many pizzas. The trip doesn't cost them too much.
3. Irregardless of the similarities, you've noted the New York Post is different than the New York Daily News.
4. Nancy washes the car, folds the newspapers and then, she delivers it.
5. Hurrying across the street, the brownish red car almost hit Larry.
6. "He has a bite on his line!", Janice exclaimed as she runs to help her brother.
7. The Boston common, a public area in downtown Boston, is the main setting for the short story "The Patriot".
8. Because my mom and dad, I believe, wanted to move when their kids had grown.
9. The television show "The Price is right" is on too early, I was still at school when it began.
10. David recklessly drove the car into the Lot, hurriedly flung the door open and then, he rushed into the building.
Explanation:
it just really means to designate something so I'm not really sure which one would be your answer if A B C or D but try to look for the one that's closest to this ignite something please mark me brainless