Final answer:
A mechanical breakdown insurance policy typically covers unexpected major system failures, such as engine failure, and does not cover routine maintenance, tire punctures, or cosmetic damage.
Step-by-step explanation:
The question asks which type of coverage would be included under a mechanical breakdown insurance policy. Mechanical breakdown insurance, sometimes also referred to as car repair insurance, typically covers the cost to repair or replace a car's major systems and components that fail due to mechanical failure or faulty manufacturing. This does not include issues that arise from normal wear and tear, routine maintenance, or damage caused by accidents or environmental factors.
So, the answer to the question is: a) Engine failure may be covered under a mechanical breakdown insurance policy. In contrast, b) Routine maintenance, c) Tire punctures, and d) Cosmetic damage are not covered because maintenance is a regular expense, tire punctures are often caused by road hazards, and cosmetic damage usually results from accidents or environmental effects, which are typically covered under different types of insurance policies such as collision or comprehensive insurance.