Why is it rare for frames to be completely accurate? choose the correct answer below. a. it is rare for frames to be accurate because frames are obtained in a way that causes the sample to favor one part of the population over another. b. it is rare for frames to be accurate because individuals that were selected to be in the sample do not always respond to the survey, which can create nonresponse bias. c. it is rare for frames to be accurate because frames are obtained periodically, whereas populations are constantly changing. d. it is rare for frames to be accurate because large sample sizes used in frames almost always result in data-entry errors.