Updates on themselves???

Please look at the following question.

" All surgeons are required to file every medical updates on ____ to guarantee accuracy of the information.
A) theirs B) them C) their own D) themselves.

The correct answer is C)their own. It means "by themselves". But I don't know on what the question is asking me about.
"They" can indicate somebody and also can something.
Can't I write "them" as the meaning of "medical records" there?
I think I can put theirs as the meaning of "medical records of all surgeons" there.
Am I wrong?
Couldn't someone explain to me why the correct answer should be only D)themselves?

Thank you for your answer in advance.