Regarding narcolepsy, which of the following statements is FALSE?
a. Maintaining a high level of emotional excitement, such as laughing, tends to prevent the occurrence of narcoleptic episodes.
b. People with narcolepsy tend to fall directly into REM sleep.
c. There is no known cure for narcolepsy, but a drug named sodium oxybate reduces the frequency and intensity of the attacks.
d. The hereditary basis for narcolepsy has been confirmed by the breeding of several generations of narcoleptic dogs.