Which statement best expresses the central idea of the text?

A. Teenagers require a unique amount of sleep to fully function, which depends on their specific age and the individual demands of their body.

B. Adults who did not get enough sleep during their teenage years showed slower mental development than those who did get enough sleep.

C. Teenagers function better during the day if they are allowed to follow their internal clock and sleep as much as they can.

D. Sleeping for 8-10 hours a night supports teenagers’ mental development and guarantees that teens perform better in school.