The correct answer is: C. Both A and B
A decrease in the own price of a commodity will lead to an extension of demand, while an increase in the own price of a commodity will lead to a decrease in demand. This is because, when the price of a commodity decreases, consumers will be able to purchase more of it with their given budget. This will lead to an increase in the quantity demanded of the commodity. Conversely, when the price of a commodity increases, consumers will be able to purchase less of it with their given budget. This will lead to a decrease in the quantity demanded of the commodity.
Here is a diagram that illustrates the relationship between price and quantity demanded:
[Diagram of a demand curve]
The demand curve is downward-sloping, which indicates that there is a negative relationship between price and quantity demanded. This means that, as the price of a commodity decreases, the quantity demanded of that commodity will increase. Conversely, as the price of a commodity increases, the quantity demanded of that commodity will decrease.
I hope this explanation is helpful! Let me know if you have any other questions.