Here are the odd ones out for each set:

1. **2. B. exercise** - All others are types of pain or medical conditions.
2. **4. B. computer** - All others are health-related terms.
3. **5. A. spots** - All others refer to illnesses or conditions.
4. **6. C. hot** - All others are health-related issues (i.e., symptoms or conditions).
5. **7. B. vegetarian** - All others are relatives or family roles.
6. **8. C. children** - All others are health-related terms.

Let me know if you need further assistance!