You Are Socializing with Your Friends Rolanda and Zackary

Multiple Choice

You are socializing with your friends Rolanda and Zackary. Another couple who you don't know, Alyse and Tyn, joins the gathering. You see Rolanda and Zackary discipline their son with a tap on the hand for sticking his fingers in the potato salad and you see Alyse and Tyn discipline their daughter by tapping her bottom for throwing the potato salad. You react with harsher judgment to the punishment by Alyse and Tyn than to the punishment by Rolanda and Zackary. One potential reason for this discrepancy could be:

A) social desirability.
B) observer bias.
C) artificiality.
D) external validity.