V01-18

Official Solution:


Hyperkalemia is a potentially fatal condition found most often in kidney dialysis patients that causes pain, severely erratic pulse, and tissue swelling throughout the body. Hyperkalemia is the result of extremely high levels of potassium in the blood and, in an emergency, can be treated with an injection of calcium chloride. However, since calcium chloride destroys surrounding tissues if it escapes from a vein, doctors overwhelmingly prefer preventative treatments. Nonetheless Hyperkalemia is not observed after a successful kidney treatment. Therefore it may be concluded that the kidneys are at least partially responsible for removing excess potassium from the bloodstream.

Which of the following, if true, weakens the argument in the passage the most?


A. Kidneys have been proven to be responsible for removing excess of another similar mineral, sodium, from the blood.
B. Symptoms of hyperkalemia resemble those of heart attack.
C. High levels of potassium in blood does not bear the risk of damaging the kidney.
D. A neurotransmitter that is responsible for keeping the kidneys healthy also plays a crucial role in removing excess Potassium from the bloodstream.
E. Calcium supplements are found to be highly effective in the treatment of hyperkalemia.


A correlation is observed between kidney disease and hyperkalemia. A conclusion is drawn that the kidney is responsible for removing potassium (or in other words, a diseased kidney results in hyperkalemia - a cause and effect relation).

The correct option may either show a reverse cause and effect relation, i.e. excess potassium (hyperkalemia) results in kidney disease or point out another factor that results in both kidney disease and hyperkalemia.

A. If at all, this option could be strengthening the argument. If the kidney is responsible for removing excess sodium, a similar mineral to potassium, it is as well possible that the kidney is also responsible for removing potassium.

B. This option may point at some relation between hyperkalemia and heart disease, but this option plays no role in relating kidney disease with hyperkalemia.

C. This option eliminates the possibility of a reverse cause and effect relation. Therefore this option actually strengthens the argument.

D. CORRECT. This option points out another factor (lack of a particular neurotransmitter) that results in both kidney disease and hyperkalemia. Thus the causal relation that kidney disease results in hyperkalemia is attacked.

E. This option may point at some relation between hyperkalemia and calcium supplement, but this option plays no role in relating kidney disease with hyperkalemia.


Answer: D