I think its B or D, most likely D.
Answer:
the correct answer is option C
The answer is A. waterfall
To be considered as an engine , it should be a Man-made objects that could be used to produce power that creates motions.
From all the options above could be used to produce such power, but the waterfall is not made by mandkind
B when is spins it means its rotating east and west directions
The answer is Rarefaction