An Argument for the Internal Validity of Quasi-Experiments

Multiple Choice

An argument for the internal validity of quasi-experiments

A) cannot be made because of inherent threats to internal validity in these designs.
B) can always be made solely on the basis of the results of the quasi-experiments.
C) can only be made if a corresponding true experiment has been done.
D) can be made on the basis of supplemental data and logical analysis in addition to the results of the quasi-experiment itself.