Answer the following question: Answer the following question given this paragraph: One example is type 1 diabetes . In this disease, the immune system attacks cells of the pancreas. Other examples are multiple sclerosis and rheumatoid arthritis. In multiple sclerosis , the immune system attacks nerve cells. This causes weakness and pain. In rheumatoid arthritis , the immune system attacks the cells of joints. This causes joint damage and pain. Q: What system is involved in diseases that include type 1 diabetes, rheumatoid arthritis and multiple sclerosis? Choices: - circulatory system - nervous system - digestion system - immune system A:
Answer:
immune system