A research study in which evaluation is performed using a control group that is similar to the experimental group, but not selected at random or specifically matched is a

The answer is Option C, a nonequivalent control group design.

Explanation:

One of the most used research designs in research about social phenomena is the non-equivalent groups design. It resembles the pretest-posttest format used in randomized experiments, but there is no random assignment. In the non-equivalent groups version, the researcher often selects groups they feel are similar to the original experimental group, like choosing another classroom from the same grade at a different school in the case of educational research. This cannot be as similar however if both groups were randomly assigned as the researcher actively performing the selection of an entire group might allow some bias to enter the selection.