I once had a nightmare set of one where I was setting things up over the phone and had to do KBAs, and asked me who held my Auto Loan. A. Who has my loan has changed since I got it originally. B. The options they gave were (Names changed) Wachovia, Ally Bank, Ally Bank Inc, Ally Bank of New York, where the original lender was Wachovia, and I know it got sold to Ally at some point.

I literally have no way to know which one of these they think is correct. At least 2 of them were correct at some point, depending on how up-to-date the data was, and the last three were indistinguishable, even when looking at my actual statements for my loan... So I failed out of my KBAs 4 straight times because they kept giving different variants of the same question, just with different sets of answers, until I could venn diagram out which one must be right because it was the only one that came up in all 4.