All of the following behaviors will compromise your immune system's ability to fight infections except
a. eating junk food.
b. exercising regularly.
c. not getting enough sleep.
d. excessive alcohol consumption.

Karen is waiting by the lockers before school for her friend richard. they had agreed to look over the history review sheet together to be ready for the test later that day. richard shows up late with uncombed hair and wrinkled clothes. karen: "you're five minutes late and you look like a wreck! " richard: (slams his locker) "you know, i don't have time for this." karen: "fine! figure out the test on your own! "