A woman who has had surgery for colon cancer asks the nurse why the doctor has her come back for a blood test called CEA. What is the best response for the nurse to make?

C CEA is used to monitor your blood to be sure you are not having side effects from the treatment.' A You should ask your physician about specific tests.' D CEA levels should increase as your general health increases.' B High levels of CEA are found in cancers of the colon; continued low levels after surgery indicate that there is probably not a recurrence.'