In Which of the Following Cases Should a Behaviorally Based

In which of the following cases should a behaviorally based rating instrument be used?

A) If valid output measures are available.
B) If valid input measures are available.
C) If the appraiser is aware of the behavior required for the job and has the opportunity to observe that behavior.
D) If the appraiser is aware of the behavior required for the job but does not have the opportunity to observe that behavior.