- A necessity to purchase the product or commodity.
- The desire to purchase or buy the product or commodity.
- Utility of a product.
- Ability to buy.
Answer d: Ability to buy.
Explanation: A want or a need turns into a demand just when it is supported by the capacity or the ability to buy. The interest or demand of a product alludes to the craving or desire to purchase the product upheld with the buying power.