Jeopardy! had a credit card category. I knew the answers to the first four questions but was unable to answer the fourth. Perhaps it was because I hadn't finished my coffee before I read the question. Or maybe I didn't see the light enough to notice that they wanted to know what the second letter stood for.These are the answers.American Express Verification Diners Club Discover Card Grace Period American Express Verification Diners ClubWhich ones did you get right? Did you, too, fail to answer the question form?(HT: Miles Earn & Burn)