Answer: c. Cost of fuel used in transporting cars and car parts.
d. Wages paid to workers in car factories.
Explanation:
Internal cost is the monetary price paid for the processes involved in constructing, managing and designing a particular product. These costs directly affect the business production processes. Examples include the cost of machinery, fuel, labor, etc.
External costs, however, are the price paid for harm or damage done to the environment or society. They do not directly affect business production processes. The society pays for it through tax.
In the list of options provided, the cost of fuel used in transporting cars and car parts directly affects the business. So also, is the cost of labor.