Answer:
a. made an external attribution.
Explanation:
External attribution: In social psychology, the term has been introduced by Heider, who has given the attribution theory in which he has mentioned that there are two types of attribution i.e, internal and external.
External attribution: The term external attribution is defined as the phenomenon in which an individual infers the situational factors as the reason behind the other person's behavior, and also referred to as situational attribution.
In the question above, Celine has made an external attribution.