Which of these is not an example of a situation that would create inaccuracies in the sampling of an opinion poll?
a. number of respondents is too small, creating a margin of error that is too large
b. questions in the poll are misleading and responses don't reflect beliefs
c. too many people screen their telephone calls or refuse to answer questions
d. people who are home during the day to answer questions are significantly different from the population that isn't home
e. telephone polls don't include people with unlisted numbers or who don't use phones