Paragraph 3 tells us that too much caffeine can result in ______.

A．many people may drink coffee when they feel fatigued
B．people consume at least 200 milligrams per day of caffeine
C．caffeine will not affect people who build up a certain tolerance for it
D．people should not drink coffee, tea, cola drinks, or eat chocolate bars

A．caffeine users can sleep longer than non-users
B．non-users usually fall asleep more easily than caffeine users
C．caffeine can help people to fall asleep
D．caffeine users wake up more early than non-users