Jon is working on a city councilperson’s election campaign. he wants to survey potential voters about their opinions. which is the best way for him to gather a sample?

a. attend a speech given by the councilman and survey audience member.
b. select every 10th person on a list of registered voters and call them to complete the survey.
c. go to the gym during the day and survey people as they exercise.
d. hand out flyers at the supermarket asking people to call and complete a survey.