Is that not correct? (Of course I fully accept your expertise in this matter and this is just my curiosity, not trying to tell you you're wrong!)
> So, MOND reduces the discrepancy in clusters at these radii to only a factor of ∼2−3 (Sanders, 1999; Ettori, et al., 2019)
So I think you're right, and today I learned something! I also checked if Stacy McGaugh had weighed in on this particular subject, and it seemed like there is still an issue for clusters [2], although interestingly the issue isn't mentioned in his latest blog post that summarizes the strengths/weaknesses with MOND [3]. Anyway, thanks for humoring me for a bit.
[1] http://www.scholarpedia.org/article/The_MOND_paradigm_of_mod... [2] https://tritonstation.com/2021/02/05/the-fat-one-a-test-of-s... [3] https://tritonstation.com/2023/06/27/checking-in-on-troubles...
If this is so, then a multi-choice question which conflates one particular MOND theory for MOND itself, and which depends on the specifics of that particular theory for selecting the 'correct' answer, is problematic: for one thing, it may make selecting the 'correct' answer more difficult for a student who has specific knowledge about the topic. This is just one of several problems with multi-choice questions, though, fortunately, it does not seem to have any bearing on the very interesting phenomenon you have discovered.
I've noticed somewhat similar behavior while training graph neural networks to model physical systems, except that it takes way longer than a single epoch to get there. Or course, there's no pretending involved with my GNNs, but the models do have very constrained representations, so once they start to figure out how to represent the physics at hand, the loss plummets dramatically.