A town’s athletic league contains 18 baseball teams. The board members of the league want to survey adults attending games to determine if they believe the athletes are showing good sportsmanship. The board members attended one game and surveyed an equal number of adults supporting each of the two teams. Which best explains the validity of the results?

A).invalid because of biased sampling
B).invalid because the sampled adults are not part of the population
C).valid because an equal number of adults supporting both teams were surveyed
D).valid because adults are the target population