In 1972, psychologist Richard Bootzin introduced a new method- the stimulus control approach- which was designed to re-associate the bed and bedroom with sleep. Bootzin theorized that when the timing of bedtime and the setting of the bedroom become associated with repeated unsuccessful attempts to sleep, then as time passes on, they become cues that maintain the insomnia. The stimulus control method achieves its goal of positive associations by curtailing sleep-incompatible activities in the bedroom. In doing so, it helps individuals to establish a consistent sleep-wake schedule. Which of the following best expresses the essential information in the highlighted sentence? Incorrect answer choices change the meaning in important ways or leave out essential information.