Susan Conducts a Telephone Survey About Offshore Drilling

Susan conducts a telephone survey about offshore drilling.The people who respond to her calls are overwhelmingly senior citizens,with very few young adults answering her survey questions.Her sample is likely to be ____________________.

A) biased, because younger and older voters hold different opinions on the issue
B) biased, if more older voters than younger voters responded
C) biased, because she did not randomly select her respondents
D) unbiased, if younger and older voters hold similar opinions on the issue
E) unbiased, because the age of a respondent does not matter