1. The problem asks: What did Avery use to destroy proteins, lipids, and carbohydrates to show that DNA was the transforming factor? 2. This is a biology question related to the experiment by Oswald Avery. 3. Avery used specific substances to selectively destroy different molecules to identify which was responsible for transformation. 4. The key method was using **enzymes** that break down proteins, lipids, and carbohydrates but leave DNA intact. 5. By destroying these molecules and observing that transformation still occurred, Avery concluded DNA was the transforming factor. 6. Therefore, the correct answer is **Enzymes**.