________ validity involves the demonstration of causality

When applying __________, the decision maker asks whether he or she can do better than a given reference point, but the value placed on outcomes depends on how far from the reference point they are

Fill in the blank with the appropriate word.

Which type of case study investigates multiple research entities for the purpose of cross-unit comparison?

A) Snapshot case study B) Longitudinal case study C) Pre–post case study D) Comparative case study