Why is it important to get enough sleep each night

It helps you function the next day. Plus if you don't get enough sleep, you may face serious health problems in the future.

It gives you rest, helps you function the next day, and is important to your physical health. It decreases the risk of getting heart disease, kidney disease, high blood pressure, stroke, and diabetes.
hope this helps!

Iwould say a is correct

Because without physical activity, the body has extra "energy" if you will, and so when it is time for bed you are not tired, so you end up staying up all night. also there is probably an effect on your internal clock, which messes with your melatonin production which goes hand in hand with your sleep cycle