Observation: You saw/ observed something and you are stating that.
Inference: You are predicting something to be true. If so and so, then this will occur.
Hey there!
the answer is
C. a tennis racket striking a tennis ball
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OFFICIALLYSAVAGE2003
One side of the mountain that has constant wind and rain blowing onto it, is more likely to catch what is falling than the other side leaving it dryer.