TIMED PLEASE HURRY :) A therapist is studying the effects of meditation and yoga on reducing stress. He offers the treatments to a random sample of 30 of his patients and lets them choose which treatment they want to use.

Which of the following statements is not true about this experiment?

A The therapist let the patients choose the treatment; therefore, he will not be able to tell which treatment is more effective.
B The therapist used a random sample of 30 of his patients; therefore, he will be able to tell which treatment is more effective, yoga or meditation, in reducing stress.
C The therapist did not use random assignment; therefore, the variability between the patients is not evened out, and he will not be able to tell which treatment is more effective.
D The therapist used a random sample; however, the patients may choose which treatment they prefer, and their stress would be reduced due to their preference instead of the treatment.