What article under UCMJ covers disobeying a lawful order to a commissioned officer?

I've been studying for the promotion board towards SSG with one of my battle buddies for the past 2 months. Recently we sat in my car and he stated, " Article 91 under UCMJ covers disobedience towards non-comissioned officers, warrant officers and petty officers but does that include officer ranks?". I sat back and thought to myself that a warrant is commissioned just as the officer ranks once they obtain the rank of Chief Warrant officer 2 but I don't recall article 91 addressing officer ranks. Eventually I responded to him saying, "I think article 89 or 92 (I was leaning towards article 92) is the article referring to the more accurate article towards the officer ranks. What are your thoughts?