Final answer:
In a client with Graves' disease, the nurse should teach them to immediately report yellowing of the skin, which can be a sign of liver damage. Therefore, the correct option is D.
Step-by-step explanation:
Propylthiouracil (PTU) is prescribed for a client with Graves' disease to control the symptoms of hyperthyroidism. While PTU is generally well-tolerated, there are certain side effects that clients should be aware of and report immediately to their healthcare provider. In this case, the client should immediately report yellowing of the skin (option d). Yellowing of the skin can be a sign of liver damage, which is a rare but serious side effect of PTU. The healthcare provider should be notified so that appropriate action can be taken.