Which of the Following Would Shift the Supply Curve for MP3

Multiple Choice

Which of the following would shift the supply curve for MP3 players to the left?

A) an increase in the price of an input used to produce MP3 players
B) a decrease in consumer tastes for MP3 players
C) an increase in the number of firms that produce MP3 players
D) an increase in the productivity of the workers who produce MP3 players