Which action will prevent this read of infectious diseases?

Eating junk food.
Drinking a lot of soda
Going to school when sick
Washing hands

Can someone plz help me on this?

You are assessing an 86-year-old postoperative patient who has an unexpressive, stoic demeanor. when you enter the room, the patient is curled into the fetal position and your assessment reveals that his vital signs are elevated and he is diaphoretic. you ask the patient what his pain level is on a 0-to-10 scale that you explained to the patient prior to surgery. the patient indicates a pain level of “three or so.” you review your pain-management orders and find that all medications are ordered prn. how would you treat this patient's pain?