An example of a preventive antioxidant is:: (A) Catalase, (B) Tocopherol, (C) Superoxide dismutase, (D) Urate
Answer is A. Antioxidants fall into two classes:

Preventive antioxidants, which reduce the rate of chain initiation.  ex: Catalase and other peroxidases such as glutathione peroxidase.
Chain-breaking antioxidants, which interfere with chain propagation.  ex: Superoxide Dismutase, Uric Acid, Vitamin E (Most powerful).

Key Concept:
Catalase falls into preventive anti-oxidants which reduce the rate of chain initiation.
Ref : Harper’s illustrated biochemistry, 31st edition.