Explanation:

- Capital Good:

- A car for a taxi operator is used to provide transportation services.

- It's an investment in a durable asset to produce other economic services.

- Intermediate Good:

- Intermediate goods are used to produce final goods or services but aren't sold to end consumers.

- A car used by a taxi operator isn't processed or sold to another producer, so it doesn't fit this category.

- Final Good:

- A final good is one that has been purchased for final use by the consumer.

- The taxi operator uses the car directly, not for resale, hence it's a final good.

- Both (a) and (c):

- The car serves dual roles; it's a capital investment and is used directly by the taxi operator.

Correct Answer: Option 4 - both (a) and (c)