I think it's D, the others either don't have enough punctuation or they have too much
Sleep helps to fuel your brain and your body. Teens need more sleep because their bodies and minds are growing quickly. Scientific research shows that many teens do not get enough sleep. To be at your best, you need between 8 and 10 hours of sleep every day. Additional sleep supports their developing brain, as well as physical growth spurts. It also helps protect them from serious consequences like depression or drug use.
