Wanda has chronically had poor sleep habits. she often remains awake in bed for hours before being able to fall asleep and sometimes becomes worried about the next day as she attempts to rest. in addition to having difficulty falling asleep, wanda wakes up in the middle of the night several times per week and is unable to fall back asleep most of the time. her lack of adequate quality sleep is starting to cause her problems at work and she is becoming very frustrated. wanda is most likely suffering from which of the following?

insomnia
narcolepsy
sleep apnea
hypersomnia