Autility company hires pollsters to knock on random doors in different parts of town to survey residents about the cost of their electric bill. which type of bias could affect this study? .

a.) lack of access.
b.) nonresponse.
c.) voluntary response.
d.) undercoverage

For this item and the choices we are given, I go with nonresponse. Thus, the answer is letter B. This process of surveying is one of the best there is; however, it faces the disadvantage that not every owner of the homes who have chosen may be kind enough to lend you some of their time to answer the questions.