Step 1: Understanding antioxidants.
BHA (Butylated HydroxyToluene) is a synthetic antioxidant commonly used in food and cosmetics to prevent the oxidation of fats and oils.
Step 2: Analyzing the options.
(A) Pentaerythrityl stearate: This is an ester used as a stabilizer in the plastics industry, not an antioxidant.
(B) Aspirin: Aspirin is an anti-inflammatory drug, not an antioxidant.
(C) BHA: This is the correct answer, as BHA is a widely used antioxidant.
(D) Penicillin: Penicillin is an antibiotic, not an antioxidant.
Step 3: Conclusion.
The correct answer is (C) BHA.