The Purpose of a Delayed Pre-Test Is To

The purpose of a delayed pre-test is to:

A) Assess the normal amount of change that occurs between two measurements before the introduction of the independent variable.
B) Assess the amount of change that occurs between two measurements after the introduction of the independent variable.
C) Allow additional time to recruit research participants to maximize sample size.
D) Determine whether observed differences between the pre-test and the post-test are maintained over time.