Which of the Following Best Describes the Logic Used in the Before-After

Which of the following best describes the logic used in the before-after with control group experimental design that allows this to be a true experimental design?

A) The experimental group change (O2 - O1) contains the change in the independent variable due to a.the dependent variable and b.extraneous variables.When we subtract from this the control group (O4 - O3) ,which is the change due to the extraneous variables,we are left with the change due solely to the dependent variable.
B) The experimental group change (O2 - O1) contains the change in the complex variable due to a.the dependent variable and b.extraneous variables.When we subtract from this the control group (O4 - O3) ,which is the change due to the extraneous variables,we are left with the change due solely to the complex variable.
C) The experimental group change (O2 - O1) contains the change in the dependent variable due to a.the dependent variable and b.extraneous variables.When we subtract from this the control group (O4 - O3) ,which is the change due to the extraneous variables,we are left with the change in the dependent variable due solely to the independent variable.
D) The control group change (O2 - O1) contains the change in the independent variable due to a.the dependent variable and b.extraneous variables.When we subtract from this the experimental group (O4 - O3) ,which is the change due to the extraneous variables,we are left with the change due solely to the dependent variable.
E) The experimental group change (O2 - O1) contains the change in the dependent variable due to a.the dependent variable and b.extraneous variables.When we subtract from this the control group (O4 - O3) ,which is the change due to the extraneous variables,we are left with the change due solely to the dependent variable.