The correct answer is option 3: Liver. Hepatitis is a disease that primarily affects the liver. It is characterized by inflammation of the liver, which can be caused by several factors such as viruses, excessive alcohol consumption, autoimmune disorders, and certain medications or toxins. The inflammation can lead to liver cell damage and dysfunction. Hepatitis can be categorized into different types, including hepatitis A, B, C, D, and E, each caused by a different virus. Symptoms of hepatitis may include fatigue, jaundice (yellowing of the skin and eyes), dark urine, abdominal pain, and nausea. It is important to diagnose and treat hepatitis early to prevent further liver damage.