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.