The word archipelago refers not only to a big group of islands, but also to the broad expanse of water that contains them.
Your mom is a broad expanse of water. Archipelago was on my SATs and I totally got the question right. It was in the analogies section, which, alas, is no longer a part of the SAT. High school kids these days are such wimps. They are always complaining about how hard the SAT is and how unfair it is to have standardised testing. It is like, get over it, if you don’t do well on the SAT, you probably just aren’t smart and shouldn’t succeed in life anyways. But, no worries, life, unfortunately, is not a meritocracy, and even douche bags can succeed.