Distinguish between interference and non-interference engines and explain why this matters when replacing a timing belt/chain.

• A. In an interference engine, pistons and valves can contact each other if timing is off, causing severe damage; in a non-interference engine, valve contact is unlikely but timing still harms performance.
• B. In an interference engine, valves never touch pistons even with timing errors.
• C. Non-interference engines always suffer piston-to-valve damage if timing is off.
• D. Only interference engines require timing belt maintenance.

Answer: (A)