Well..
Top boffinry all round!
"The third option is that Einstein's theories of gravitation are wrong, or at least in serious need of revision."
Trouble is if that is true, just what the the hell are we supposed to change in Einstein's equations? Anyone got any ideas as to what should be changed?
Einstein himself didn't like the original form of his equations, and was pleased that Hubble's findings allowed him to get rid of an ugly and implausible constant.
The one thing is this. Relativity and quantum mechanics do not agree with each other, so something is wrong somewhere.