I think I have just come across a great, controversial topic. As far as I know, the etymology of the word 'OK' has not reached a consensus yet, and it probably never will.
It seems that Oxford goes for the 'oll korrect' version (to me it seems the most plausible, credible) (link). However, this explanation (link) seems plausible, too.
So, what do you think?
Student or Learner