The supply and demand curves show data for the latest paperback edition in a popular young adult fiction series that has been turned into a film. Which change must be made to the graph if the publisher offers a complementary download of a song from the newest film version with purchase?

Add a second supply line, showing a decrease in supply and a decrease in equilibrium price.
Add a second supply line, showing an increase in supply and an increase in equilibrium price.
Shift D1 left, showing a decrease in demand and a decrease in equilibrium price.
Shift D1 right, showing an increase in demand and an increase in equilibrium price.