And by the way in the event you're denied for any other reasons and you're certain you can work around it, go ahead and email your request immediately for review to
ImmigrationVisaNairobi@state.gov
Usually they review all denials to determine whether the law allows for reprise.
You can also send any queries you have to them as well just to rule out guess work.
By all means make sure KNEC sends your confidential KCSE cert to the Embassy at least 2 weeks before your interview. This is the first document they had when we arrived. Some people were put on AP because they didn't have it. Separate your originals from your copies and ensure you keep your passport and appointment letter in hand at the gate. These two will be checked severally.
The documents they'll be most interested are originals and copies of: KCSE cert, KCPE cert, birth cert, police cert, marriage cert, DS Confirmation page, passport photos and visa fees.