Concept:An antonym is a word with the opposite meaning. Oracular means mysterious or cryptic; its opposite is clear or easy to understand.Explanation:Oracular means vague, enigmatic, or like a prophecy. It is often used for something puzzling.Lucid means clear and simple to grasp. It is the direct opposite of oracular.The other options do not match: Impress means to affect someone strongly; Anxious means worried; Idealistic means guided by high ideals.Thus, the antonym of oracular is lucid.Answer:Option A (Lucid).