A state representative wants to know how voters in his district feel about enacting a statewide smoking ban in all enclosed public places, including bars and restaurants, as well as several other current statewide issues. He mails a questionnaire addressing these issues to an SRS of 800 voters in his district. Of the 800 questionnaires mailed, 152 were returned. The sample is A) the 800 voters receiving the questionnaire. B) the 152 voters returning the questionnaire. C) all voters in his district. D) none of these