I'm pretty sure this is one of those errors...counting the "lines" between the ketones gives you 3, so the answer should be D. 🤔 Cause the lone methyl groups will not combine together lol...so I'd say this is an error! Don't worry about it too much. It's good practice, but BC and Destroyer will help too, and don't have nearly as many errors as the 2009 test does lol.