The Waukon School District is trying to determine whether to build a new outdoor stadium. The school board sent a survey home with the members of the football and track teams so that data could be collected regarding how many community members favored the construction of the stadium. The results of the survey were not valid. Which statement indicates what should be changed to get valid results? A. The survey should include the teachers.

B. The survey should be sent home with the members of all sports teams.

C. The survey should include only freshmen who are members of sports teams.

D. The survey should include a representation of all households in the school district.