Consider the Diagram Below A) the Nonequivalent Group Design
B) the Pretest-Posttest Control-Group Design

Multiple Choice

Consider the diagram below. Which type of experimental design is depicted?
$$\begin{array} { c c c c } \mathrm { R } & \mathrm { O } _ { 1 } & & \mathrm { O } _ { 2 } \\\mathrm { R } & \mathrm { O } _ { 3 } & \mathrm { X } & \mathrm { O } _ { 4 }\end{array}$$

A) the nonequivalent group design
B) the pretest-posttest control-group design
C) the Solomon four-group design
D) the posttest-only control group