Which of the Following Is NOT a Strategy Experimental Researchers

Which of the following is NOT a strategy experimental researchers use to designate who goes into experimental and who goes into control groups

A) pair subjects who are identical on relevant variables and assign one to the control group and one to the experimental group.
B) create groups that are equivalent in terms of their averages on some relevant variables.
C) assign subjects randomly to the experimental and control groups.
D) match subjects on relevant variables.
E) have participants from the experimental group switch places with the control group after the experiment