Explanation:

- Wheat is usually considered an intermediate good when it is used by bakeries to make bread or other products.

- Gold is typically a final good when purchased as jewelry or investment, but can also be used in industry; however, it is *not* commonly classified as an intermediate good.

- Services of a doctor are final services, directly consumed by individuals. They are not used as inputs in the production of other goods or services.

- Sand and bricks are basic materials used by builders and construction companies to create buildings, making them classic intermediate goods.

Correct Answer: Option 3 – Service of Doctor