Yes, Choice B is correct.
The core of the argument is "earthquake took place in A.D.365".
The changes before and after A.D.365 increase the possibility of the major earthquake. That is to say, if you want to support a conclusion, the answer does not have to be perfect!
However, C uses modern histories, which are not objective evidence, and it just repeat the conclusion, no new evidence!
So, can you understand?