Answer: (C) An attribution.
Explanation:
An attribute is the term that refers to the act in which the people are explaining about the events and others behavior.
It is the process in which the people are giving credits to the other about their quality and the personal characteristics.Internal attribute is one of the type of an attribute.
According to the given situation, Professor chu explaining about the exam performance of his students is an example of an attribute.
Therefore, Option (C) is correct.