How many episodes did the South Park season featuring the episode "Casa Bonita" have?
Casa Bonita (South Park): "Casa Bonita" is the eleventh episode of the seventh season of the American animated television series "South Park", and the 107th episode of the series overall. South Park (season 7):  The seventh season concluded after 15 episodes on December 17, 2003, and was written and directed by Trey Parker.
15