Assume the Graph Shown Represents the Market for Button-Up Shirts

Assume the graph shown represents the market for button-up shirts and was originally in equilibrium where demand (D) and supply (S) intersect. What type of shock might cause the demand curve to shift to D₂?

A) An increase in the price of buttons
B) An increase in the price of ties
C) An increase in the price of sweatshirts
D) An increase in consumers' incomes