Why were a few of the alpha particles deflected at wide angles when they passed through the gold foil?

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.

if your own plato the answer is b. the fern transitioned from sporophyte generation to gametophyte generation.