A pharmacy wants to survey its customers to find out which brand of toothpaste they prefer. Which survey methods are likely to be biased? Select each correct answer.
A: A survey is sent to the customers who are on the pharmacy’s frequent buyer list. B: Those customers who buy toothpaste with a coupon are selected, and the toothpaste brand they purchased is recorded. C: One hundred people from the pharmacy’s customer list are selected at random, called on the phone, and asked. D: Every 10th customer who enters the pharmacy on 1 day is selected and asked.