Which of the following alternatives is NOT correct?

Which of the following alternatives is NOT correct?

A) Randomization is used in the experimental method to assign participants to groups.

B) Randomization is used in the nonexperimental method to eliminate the influence of third variables.

C) Randomization is used to ensure that participant characteristics will be evenly distributed between different groups.

D) Randomization is used when it is difficult or impossible to hold an extraneous variable constant.