Someone tried several different psychological therapies because of a mental illness: psychoanalytic therapy, cognitive-behavioral therapy, and sandbox therapy. He said, "The psychotherapy process makes me very unhappy, so these therapies are ineffective. ". Which of the following, if true, would most effectively challenge the above conclusion? ['The mental illnesses targeted by several different psychological therapies are different.', 'People who try multiple psychotherapies are happier than people who try only one.', 'Trying different psychotherapy at the same time makes it easier to find a way to work.', 'People with good treatment tend to feel unhappy during treatment.']