The best answer to the question is:
b. comerciantes
Explanation:
1. The term "LOS" typically refers to a group of people or individuals.
2. The phrase "se dedican a la compra y venta" translates to "they are dedicated to buying and selling."
3. Among the given options, "comerciantes" directly aligns with the activity of buying and selling, making it the most appropriate choice.
4. Comerciantes are individuals engaged in commercial activities, such as buying goods from suppliers and selling them to customers for a profit.