okay

the only acceptable way to say "OK/ok". while "okay" looks pretty, the other spelling variations of the word look dumb. however, if "Ok/ok" is part of a phrase that is culture-relevant, it is alright to use.

Person 1: Ok, no problem.
Person 2: ew why'd you use "ok" instead of "okay"?
Person 1: It takes less time to time
Person 2: ok boomer