The correct answer is option 3: Trypsin and Amylase.

Enzymes are proteins that catalyze chemical reactions in living organisms. Each enzyme has an optimal pH range in which it functions most effectively. Some enzymes work best in acidic conditions, while others prefer alkaline or neutral conditions.

Option 1 states that trypsin and pepsin do not work at acidic pH. This is incorrect because pepsin is actually an enzyme that works in the stomach, which has an acidic pH (around pH 2).

Option 2 states that chymotrypsin and pepsin do not work at acidic pH. This is also incorrect because pepsin, as mentioned earlier, functions at an acidic pH.

Option 3 correctly identifies that trypsin and amylase do not work at acidic pH. Trypsin is an enzyme that functions in the small intestine, which has a higher pH than the stomach. Amylase, on the other hand, is an enzyme that breaks down carbohydrates and works best in neutral or slightly alkaline conditions.

Option 4, which suggests that pepsin and amylase do not work at acidic pH, is incorrect. Pepsin, as previously mentioned, is an enzyme that