Correct choice is (c) Kidney
For explanation I would say: Liver and Kidney are both responsible for filtering and purifying the blood. If the kidney has been transplanted because it had been harmed by toxins, then the same toxins could have harmed the liver as well. A transplanted kidney will require the use of immuno – suppressants to reduce the risk of immunorejection. This can put further pressure on the kidney and damage it.