Na2SO4 + Sr(NO3)2 ->

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.

you did not give any options thus this is the best answer i can give to you with this little information you have given

> they are both natural and not man made

> they can be tracked and predicted by the right tools

-love shrooms

the right answer is c i just did the question.