Which of the Following Is an Example of a Halo

Which of the following is an example of a halo effect?

A) Shawn unknowingly tends to rate his new client's behavior slightly higher during testing after noticing the client is wearing a class ring from his own alma mater.
B) Kenneth tends to distrust all instructors, regardless if they are new or if he has had them for multiple classes.
C) Emilee always seems to like the last person she interviews for a job because she remembers the most about them.
D) Wyleen provided her diagnosis only after conducting her own assessment and compiling information from two of her professional colleagues.