In 1988, 50 people with emotional disturbances underwent hypnosis to be cured of their mood swings. A follow-up survey in 1993 revealed that five had fairly stable emotional conditions at the time of the survey. These five subjects can therefore serve as models of the types of people for whom hypnosis is likely to be successful.

Which of the following, if true, casts the most doubt on the suitability of those five subjects as models in the sense described?

(A) The five subjects have very different personalities and backgrounds.

(B) Since 1988, the five subjects have experienced dramatic mood swings interspersed with periods of relative stability.

(C) Those people who were still suffering from unstable emotional conditions at the time of the 1993 survey had shown no improvement since 1988.

(D) Many psychologists are less concerned about a patient's mood swings than about the patient's willingness to express his or her problems and fears.

(E) The emotional condition of most of the 45 subjects who were still unstable at the time of the 1993 survey had actually worsened since 1988.
_________________