[ng-user]

I agree with another commenter that "Which face is real?" is somewhat easy to determine. In this scenario, it's A or B. You already know one face is fake, and one is real. It would be substantially more challenging if the question was rather "Can you spot all the AI generated faces?" and it turns out 40% of the time there is no AI generated face at all.

AI vs. Real can become somewhat easy to identify over multiple repetitions - AI vs. Real, Real vs. Real, AI vs. AI. are all scenarios that should be included to increase the difficulty imo.