The answer would be B or D but i'm pretty sure it's B
1. Caduceus
2. Doctorate
3. Apprenticeship
4. Epidemic
5 .Homeopathy
6 .Hospitalitist
7. Biofeedback
8 .Naturopathy
9. Plague
10.Reciprocity
I think lymph nodes produce white blood cells...so when you get sick, they produce many white blood cells to fight the bacteria or virus, and I assume they swell because they're over-producing white blood cells.