You explain one or more than one topic the prompt tells you to write about.
Answer:
c) helmet:protect
Explanation:
Because the given analogy has a statue, which is the object in question, as the first listed part and memoralize as the second part, the reason that statues are made. Helmets are the object in question and their purpose is to protect just like a statues' purpose is to memoralize.
Secondary source is more like say you were at home and your friends tell you about a Party in the phone he's giving you information since it weren't there