Which of the Following Best Describes the Trend in Nonresponse

Multiple Choice

Which of the following best describes the trend in nonresponse rates in telephone surveys conducted from 1979 to 2003?

A) Response rates have continually increased.
B) Response rates have remained unchanged primarily due to the effects of online surveys.
C) Response rates have slowly declined over this period of years.
D) Response rates increased dramatically from 1979 to about 1988, and then saw a downward fall that was just as dramatic.
E) Response rates increased dramatically from 1979 to about 1985, and then saw a downward fall that was just as dramatic.