Exhibit 10-10: Identify the Major Threat to Internal Validity in the Following

Multiple Choice

Exhibit 10-10: Identify the major threat to internal validity in the following research studies.
-Refer to Exhibit 10-10.A researcher used two classrooms in an experimental study.It was found that the E group had more high ability students than the C group before the study began.

A) Regression
B) Diffusion
C) Mortality
D) Selection bias
E) History