Answer:
b. Respondents may exaggerate or distort facts.
c. Respondents might consider the survey to be junk mail.
e. Respondents may not represent an accurate population sample.
Explanation:
There are a lot of disadvantages to that type of survey. It is impossible to guarantee that the respondents will be the desired target public, they can answer anything and you will not be there to adjust the question to make the respondent give a clear and valid answer, the respondents can throw away the mail mistaking it for junk and there is the possibility of a very low answer number, making the survey incomplete.