The students in Anthony's anatomy class are used to studying for biology classes and most of them pair up into "study buddies" before the class begins. When writing exams for the class, Anthony doesn't proofread the exams and her students find that she isn't receptive to their questions. When the students do poorly on the first exam of the semester, it is most likely due to

A. testing error.

B. method error.

C. interrater error.

D. trait error.