What types of error might be associated with the following situations?

a. Conducting a survey about attitudes toward city government using the telephone directory as a sample frame.

b. Interviewing respondents only between 8:00 a.m. and 5:00 p.m. on features they would like to see in a new condominium development.

c. Asking people if they have visited the public library in the past two months.

d. Asking people how many tubes of toothpaste they used in the past year.

e. Telling interviewers they can probe using any particular example they wish to make up.