Was it a misdemeanor or felony?
If it was a series issue that landed you in the clink, I’d suggest declaring it and using the ‘explain more:’ or whatever field, since it doesn’t seem to be a serious crime it wont matter much either way. China will let you get a tourist visa with a minor criminal offense, as long as it wasn’t a serious crime indicating ‘moral issues’ or whatever. If it was a misdemeanor, from what I’ve heard, don’t tick the box and move on. Things are constantly changing though, so who knows.