John's Performance Was Satisfactory During the First Month,but After That

John's performance was satisfactory during the first month,but after that time,he was found to be very inconsistent in the provision of nursing care.One month before the end of the rating period,he cared for a very wealthy and influential client,who is best friends with the clinical manager.This client donated new furniture for the staff lounge in John's name to show appreciation for his care.John's subsequent performance appraisal resulted in outstanding ratings in all areas.This is an example of:

A) a performance rating based on justifiable evidence.
B) a bias related to recent events.
C) the impact of personality on the appraisal of performance.
D) the effective use of a behaviorally anchored rating scale.