The Main Problem Associated with Subject Attrition During the Course

Multiple Choice

The main problem associated with subject attrition during the course of a study is that

A) regression toward the mean on the dependent variable measure is likely.
B) the group with the most participants remaining at the end of a study will likely have higher posttest scores.
C) the researcher can no longer use statistical analysis to understand the results.
D) groups initially created to be equivalent may no longer be equivalent.