Comparing the California Test Scores to Test Scores in Massachusetts

Multiple Choice

Comparing the California test scores to test scores in Massachusetts is appropriate for external validity if

A) Massachusetts also allowed beach walking to be an appropriate P.E. activity.
B) the two income distributions were very similar.
C) the student-to-teacher ratio did not differ by more than five on average.
D) the institutional settings in California and Massachusetts, such as organization in classroom instruction and curriculum, were similar in the two states.