Exhibit 10-9: Identify the Threats to Internal Validity Illustrated in the Examples

Multiple Choice

Exhibit 10-9: Identify the threats to internal validity illustrated in the examples below.
-Refer to Exhibit 10-9.Preschoolers who received treatment for stuttering during the year show a significant improvement in articulation.

A) experimental mortality
B) reactive effect of testing
C) statistical regression
D) maturation
E) instrumentation