In 1982, 3 students out of ~300,000 caught an SAT geometry question whose correct answer wasn't among the choices. Below: the same trap, re-disguised so memorization can't help, fed live and concurrently to a field of frontier and open models — plus one agent that is not allowed to guess.
The famous 1982 original used a 1:3 ratio (true answer 4). Here the ratio is 1:4, so a model that memorized “the answer is 4” walks straight into the trap: 4 is now the wrong naive answer, and the true answer 5 is deliberately absent — exactly the original defect.
One trip around adds one extra rotation beyond the circumference ratio (the coin-rotation paradox): N = R/r + 1 = 4 + 1 = 5. The red marker points straight up five times.
60-second race cutoff: a lane with no answer by then scores DNF (its eventual answer is noted for honesty).