根据以下材料,回答36-40题
With all my kids officially back in school, a time-honored family tradition is also well underway—the evening bedtime battle. We don't play when it comes to sleep in our house. During the school year, my 3 kids under 10 have a strict 7:30 bedtime. My 10- and 13-year-olds get exactly one extra hour, and during the summer those bedtimes roll back by one hour only. I'll be honest—most of my mom friends think I'm crazy. When they hear that my kids go to bed at 7:30 they usually give a stunned laugh and say, "But why? And how?!" The why is easy. Kids need more sleep than adults in order to keep up with the demands of their rapidly growing bodies and brains—a lot more sleep, in fact. 3- to 5-year-olds need 11 to 13 hours of sleep, 5- to 10-year-olds need 10 or 11 hours of sleep, and 10- to 17-year-olds need 8.5 to 11 hours of sleep each night.
Lack of sleep increases activity in the amygdala, the emotional rapid-response center of the brain. Kids who don't sleep enough feel more negative emotions and have a diminished ability to control their responses to those emotions. An overactive amygdala inhibits kids' ability to feel positive emotions, which is why overly tired kids will cry or protest when presented with an activity they normally enjoy. Even more concerning, kids who don't sleep enough are at a much higher risk for depression, anxiety, and other emotional disorders later in life.
The highest amounts of human growth hormone are released to the body when kids are sleeping. If your child goes to bed late one night, it's not going to stunt their growth—but if your child chronically gets even an hour or two less than the amount of sleep he or she needs, physical development is likely to be affected. They'll also age faster on a cellular level. Plus, they'll be sick all the time, since sleep is when their bodies make and release cytokines, a protein that targets infection. Sounds pretty terrible, huh?
Lack of sleep literally makes learning impossible, according to researchers at University Children's Hospital Zurich: During the day, our synapses get excited as a response to the stimuli that surround us. During sleep, however, these synapses restore themselves and their activity "normalizes". Without this restorative period, the synapses stay maximally excited for too long. Such a state inhibits neuro plasticity, which means that learning new things is no longer possible.Since kids' brains are by far more neuro-plastic than adults, this means that lack of sleep has an greater effect on their synapses, depriving them of the rapid ability to learn that characterizes childhood.
Apart from those, I didn't even go into the way sleep regulates metabolism, cortisol, or motor function—it's safe to say that without adequate sleep, literally every single system in our children's bodies is severely compromised.
The author uses her own example to show______
A kids who seldom use devices later in the evening get enough sleep
B sleep deprivation creates something of a vicious cycle
C kids of 10- to 17-year-old tend to sleep less than smaller kids
D adequate sleep is crucial to the development of kids