Which of the Following Does NOT Shift the Demand Curve

Multiple Choice

Which of the following does NOT shift the demand curve for broccoli?

A) a decrease in the price of spinach, a substitute for broccoli, because of a bumper crop of spinach this year
B) a warning by the U.S. Surgeon General that broccoli causes schizophrenia
C) an increase in the cost of fertilizer used to grow broccoli
D) an increase in the price of spinach, a substitute for broccoli, because rodents gobbled up much of this yearʹs spinach crop