Assume That You Have Developed a Study Technique That You $\quad R=$

Assume that you have developed a study technique that you believe will result in students scoring higher on research methods exams.You test your study technique with the design diagramed below.
Where: $\quad R=$ random assignment
$\mathrm{O}=$ observation on the dependent variable
$\mathrm{X}=$ the independent variable
$\begin{array}{llll}\mathrm{R} & \mathrm{O} 1 \mathrm{X} & \mathrm{O} 2\end{array}$
$\begin{array}{lll}\mathrm{R} & \mathrm{O} 3 & \mathrm{O} 4\end{array}$
Using the diagramed design,what are your predictions?

A) O2 should be greater than O1
B) the (O2-O1) change should be greater than the (O4-O3) change.
C) O4 must equal O3
D) O2 should be greater than O1, the (O2-O1) change should be greater than the (O4-O3) change and O4 must equal O3
E) O2 should be greater than O1, and the (O2-O1) change should be greater than the (O4-O3) change