Great story! I think that people who construct multiple-choice tests tend to be psychologically biased toward the answer C, and it's related to zeroing in on a target distance (the first throw is too far or too short, the second throw over-corrects, and the third throw is close to the target)

It's also related to the story of Goldilocks and The Three Bears: "This porridge is too cold. This one's too hot. But this one's just right!"

And if you ask a group of people, "Choose a number between 1 and 4", you will likely find that well more that 25% of them will choose 3.

So when a question is something like "When did dinosaurs go extinct?

A. 200 million years ago

B. 5 million years ago

C. 65 million years ago

D. 105 million years ago",

you can probably guess correctly that the test creator thought the answer was C.

Of course, some of us would quibble that dinosaurs never did go totally extinct, but survived as birds. That's why I hate multiple-choice tests: There's no possibility to dispute all of the answers, though even test-creators can be wrong.