Short Answer D
I definitely wouldn't pick B. That's too heavy a topic to be amusing. Any argument having to do with misuse of the environment is is not for laughs. It is not amusing.
A is a pastoral recollection. He is thinking of something gentle and in the country but I would not call it amusing.
C
This is a description of a water cycle as performed by an elementary student. I don't think it is amusing. It is just informative.
D
Is your answer. Something like a frog just scarred the wits out of someone who is too young to know what it is. That is amusing if you like that sort of scene.