Which of the following are anecdotal and which are based on a sample?
(a) Seventy-five text messages were sent one day during a lecture by students in a large class.
(b) Erik says he gets the best bargains at online auctions by bidding on items whose termination is early in the morning.
(c) Out of 4,837 college age students in California, 3769 admitted they used a cell phone to talk or text while driving.