Dr. johannsen wants to test whether recovering alcoholics perform worse on tests of motor coordination than a group of control participants. unbeknownst to him, the control group meets at an amusement park three hours before testing and goes on as many rides as possible. they perform worse than the alcoholic group. this is an example of a(
a. regression effect.
b. selection-maturation effect.
c. regression artifact.
d. selection-history effect.

The given scenario is an example of a selection-history effect.

Option D

In group-based research, selection-history effect assesses the behaviour displayed by the test subjects before and after the test. Since it is a history threat or effect, it means the outcomes of the results will be affected by the individual’s past experiences.

The individuals in the research have different pasts, and while the control group may have performed worse, it shows that there are other factors influencing motor control. It may be a bad experience with bad driving at a younger age, or some have a phobia to driving.

the answer to your question is,

old stone age.

-mabel < 3

well this isn't a question but if you are asking if it is true or false it is, true.