If You Find That Two Groups Differ from Each Other

Multiple Choice

If you find that two groups differ from each other on the dependent measure at the end of an experiment, you are able to conclude that:

A) only one thing could have caused the difference: manipulation of the dependent variable.
B) the groups differed on the dependent measure before the study started.
C) only one thing could have caused the difference: manipulation of the independent variable.
D) none of the above