Ruben is a travel agent. He intends to sell his customers a special round-trip airline ticket package. He is able to purchase the package from the airline for $160 each. The round-trip tickets will be sold for $210 each and the airline intends to reimburse Ruben for any unsold ticket packages. Fixed costs include $5,400 in advertising costs. What is the contribution margin per ticket package? A. $370 B. $50 C. $160 D. $210