Answer: B
Explanation:
Decrease in quantity supplied occurs when the supply chain of a market is interrupted.
Looking at the answers:
A. price of cupcakes increase - this will not decrease quantity supplied, this will raise the price and decrease demand.
B. cost of ingredients for cupcakes rises - this will decrease quantity supplied. Producers of cupcakes cannot make as many cupcakes as they had in the past at the same cost due to materials being more expensive.
C. prefer cakes to cupcakes - this will decrease demand, not quantity supplied.
D. nutritional labeling regulation for cupcakes - this is irrelevant.
