According to recent medical research, sleeping more than nine hours or less than six hours a night can shorten your life expectancy. Those who are likely to live longest are people who regularly get between seven and eight hours a night.
A new survey of 1,000 adults conducted by the Better Sleep Council (BSC) found that few people understand the important role sleep plays in normal daily brain functions and many people actually reduce their brain power by getting too little sleep.
One in three adults admit that they do not get enough sleep, and lack of sleep is leaving millions of people without the energy to work as hard as they should.
Although a large number of people say that they need to be mentally alert in their work, over half of the people interviewed say that they sleep just under seven hours a night during the week.
On the other hand, most of the people interviewed say that they sleep more than seven hours a night at the weekend. This suggests that a significant number of people try to catch up on their sleep at the weekend instead of getting enough sleep during the week, when they most need it.
Question: Which sentence is not correct according to the article?
Select one:
a. People try to sleep more on weekend.
b. Enough sleep alert the brain.
c. Most people sleep less or more than usual.
d. More than nine-hour sleep a night is suggested for adults.