Answer:
The correct answer is letter "C": the quantity of coffee sold can increase if the supply curve shifts to the right.
Explanation:
The demand theory establishes the relationship between the price of a good or service and the quantity demanded. If the price rises, the quantity demanded lowers -the demand curve moves to the left. If the price lowers, the quantity demanded rises -the demand curve moves to the right.
The supply theory states a direct interaction between the price of a good or service and the quantity supplied. It means if the price rises, the quantity supplied rises -the supply curve moves to the right. If the price lowers, the quantity supplied lowers -the supply curve moves to the left.
In this case, as the demand for the coffee has expanded, it could increase if the demand rises. If the demand rises there must be more supply of coffee which implies moving the supply curve to the right.