Answer A
His whole tone is that there is wonder in snow that people don't seem to look at carefully. He proposes that you go get a magnifying glass and take a better look. What you see is astonishing and beautiful and unlike anything that snow looks like as its falling.
He doesn't argue about the temperature or the sameness of the flakes. He argues about the beauty and uniqueness of snow. B is incorrect.
He says no such thing as C. He says the changes on the ground are what should be observable. C is wrong.
D is just a 4th answer so you had 4 to choose from. He advances no such idea. D is wrong.