All the Cells in the immune system: T-cells, B-cells and NK Cells these are all types of white blood cells. so the answer is C
If this is for sport science or a similar subject then extension is defined as the movement where the angles between the bones increase.
Charlie freinds displays 2/7 of 5/6
Incase the person who is choosing to do this has some sort of health issue, when telling their doctor the doctor might have them choose a different route of dieting. This way it is sorted to their health.
Answer:
Helps protect from viruses.
