Suppose the domestic supply (Q S ) and demand (Q D )for MP3 players in the United States are given by the following set of equations: Q S = –25 + 10P Q D = 875 – 5P If the United States can import MP3 players fr om the rest of the world at a per unit price of $50 , how many MP3 players will be produced in the United States? a. 625 b. 475 c. 925