A political party sends a mail survey to 1500 randomly chosen registered voters in community. The survey asks respondents to provide an opinion regarding the job performance of the current President. Of the 1500 surveys sent out, 480 are returned, and of these, only 120 say they're satisfied with the President's job performance.
The sample is
A. The 1500 randomly selected voters receiving the questionnaire.
B. The 480 surveys returned.
C. The 120 voters surveyed that are satisfied with the President's job performance.
D. The voters in his district.