Concept:The correct word must be the most direct opposite of "fake" and fit naturally in the sentence.Explanation:"Fake" means not real or not original.Its most suitable opposite is "genuine", which means real, authentic, or original.The other options do not mean the opposite of "fake": "costly" means expensive, "durable" means long-lasting, and "perfect" means without flaws.So the sentence becomes: "Dishonest traders sell fake products instead of genuine ones."Answer:C. genuine