Attrition in Panel Studies Refers to Which of the Following

Multiple Choice

Attrition in panel studies refers to which of the following?

A) Over time, the population changes.
B) Panel members begin to tire of repeated questioning and give thoughtless, stock answers during interviews.
C) The process of sample selection must remain the same at time 1 and time 2.
D) Some members of the panel may drop out of the study.
E) The process of re-interviewing a panel of informants at multiple points in time.