From the things that make you go hmm.... department:
Choose a question like “In what city was your high school?” then enter the answer. This kind of information gives us a way to identify you that someone else won’t know or be able to fake.
In this century, I find the claim that this "significantly improves your online security" rather dubious. In the pre-2000 days before social networks and massive free databases, maybe this might have been more useful.