Which disease is caused by a virus that affects the liver?

Hepatitis is caused by a viral infection that specifically targets the liver, leading to inflammation and various complications. This disease can be caused by several different viruses, including hepatitis A, B, C, D, and E, each with distinct transmission methods and health implications.

The liver is a vital organ responsible for numerous functions, including filtering toxins from the blood and producing important proteins. When a virus infects the liver, it can disrupt these functions and lead to symptoms such as jaundice, fatigue, and abdominal pain. Chronic forms of hepatitis, particularly those caused by hepatitis B and C viruses, can lead to more severe health issues, including cirrhosis and liver cancer over time.

In contrast, diabetes is a metabolic disorder that affects how the body processes glucose, AIDS is caused by the HIV virus primarily affecting the immune system, and pneumonia is an infection that inflames the air sacs in one or both lungs, which may be caused by bacteria, viruses, or fungi but does not directly involve the liver. Thus, hepatitis is the only condition from the options provided that is directly caused by a virus affecting the liver.