When a vaccine is given to a person with a healthy immune system, what is the long-term result? your body has built up an

segmentation=endoskeleton=backbone=coelom=tissues

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.