Answer:
D) Increase in the market wage rate for pastry chefs.
Explanation:
A decreased demand may be caused by an increased wage rate of pastry chefs. Since a bakery may hire this expensive labor and produce pastries, this will result in increased cost for the bakery, this will be passed on to the consumers in turn for increased prices. Consumers will buy less of it and thus demand for pastries will fall requiring bakeries to hire less chefs.
Hope that helps.