In Which of the Following Cases Is It Advisable for an Appraiser

In which of the following cases is it advisable for an appraiser use a graphic rating scale?

A) If the appraiser is aware of the behavior required for the job and has the opportunity to observe that behavior.
B) If valid output measures are available.
C) If the appraiser is aware of the behavior required for the job and valid output measures are available.
D) If the appraiser does not have the opportunity to observe behavior required for the job and no valid output measures are available.