Which design not only controls all threats to internal validity but also controls the effect of ...

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Rationale 1: The nonequivalent control group design is similar to pretest/posttest control group design. Selection bias as a threat to internal validity is present as no random assignment to groups occurs.
Rationale 2: The Solomon four-group design is considered the most prestigious design because it minimizes threats to internal and external validity and controls the reactive effect of the pretest.
Rationale 3: In a pretest/posttest control group design, the threats to internal validity are controlled, but the threat to external validity of reactive effects of a pretest exists. The posttest design is used when a pretest is not possible.
Rationale 4: In a pretest/posttest control group design, the threats to internal validity are controlled but the threat to external validity of reactive effects of a pretest exists.

So that's it? I just the answer and what's in it for you?! Any way, I'm not complaining