Answer:
The consequence for holding the door was the presentation of a stimulus, and the behavior of holding open the door subsequently decreased in frequency; therefore, this is an example of positive punishment.
Step-by-step explanation:
Stephanie made a fuss when Alex opened the door for her, this is a reaction to behavior he had. The effect of that response acted as a positive pushishment to Alex, since the action of opening the door decreased.
Stephanie's response weakened Alex behavior.