Probably one of the first three, but my pet idea (whimsy, really) is that the universe is tightly twisted up in a high dimensional space and the gravitational distortions we see are just the "shadows" of normal matter from parts of the universe further out than we can see.
This survey is not MECE; actual mysterious god stuff might manifest as wrongmath. Also wrongmath sounds like a word from the newspeak dictionary (10th ed. expunged in 11th due to incompatibility with doublethink.)
Is there some survey where you can see the distribution of physicist opinions on the nature of dark matter?
Personally, with zero actual knowledge, my aesthetic sense says we’re never gonna find WIMPs