yeah its definitely D.
this is because the condition is found in kidney dialysis patients, thereby caused by failing kidneys; Moreover, since the condition is also caused by excess potassium, and not found in people with normally functioning kidneys, you can logically infer that the failing kidneys are the cause of the excess potassium which causes the condition. I am also pretty sure that, outside the box, kidneys do play that role in our bodies. I guess E would make sense too, but there is a possibility that the calcium chloride would not damage tissue and the tissue swelling doesnt necessarily mean damage, and doctors overwhelmingly prefer not to use the CaCl, so it could be inferred that it is an unlikely treatment. I would say with a pretty good amount of certainty that D is the correct answer because it is the only one that is mentioned in the stimulus and can be logically inferred from it.