The answer is C., because..It is called a vacutainer which is a medical device attached to patient that has an infection that requires draining.
Usually on bed sores or places wher O2 is not available. for instance/ buttocks, back of legs, or parts of the body that are not exposed to oxygen. usually the anterior( or back of body anatomically.
Mostly patients are in their 70's +. people not able to move freely..
