Identify a True Statement About Matched-Groups Experimental Designs

Identify a true statement about matched-groups experimental designs.

A) Matching with a large number of groups becomes unwieldy because it is difficult to find subjects with equivalent scores on the variables to be matched.
B) Control of subject variables is difficult because it obscures the effect of the independent variable under investigation.
C) This design works best when a matched characteristic has little or no effect on a dependent variable.
D) Lack of requirement for pretesting makes this design less demanding and time-consuming than a randomized design.