Answer:
A. A situational type phobia
Step-by-step explanation:
The fear is being around other people and correlates with that one situation where she was in a elevator and got super hot resulting in shortness of breath and other things. So she refuses to take an elevator and takes the stairs. So based on that situation she kind of has developed a phobia of elevators with a bunch of people or even doesn't want to ride an elevator at all due to her past situation. Thus being a situational type phobia.