Explanation:

- Option 1: Radio

- Radios are considered durable goods. They last a long time and are used repeatedly without wearing out quickly.

- Option 2: Clothes

- Clothes are semi-durable goods. They last for a reasonable amount of time but not as long as durable goods. They are subject to wear and tear over time.

- Option 3: Milk

- Milk is a non-durable good. It's perishable and consumed quickly, typically within a few days or weeks.

- Option 4: Petrol

- Petrol is also a non-durable good. It's consumed quickly and doesn't have a prolonged lifespan.