Fill in the blank with a suitable preposition:
A preposition is a word which comes before a noun or a pronoun and establishes a relationship between the elements of a clause or words. Option D)in is correct as it expresses a situation or surrounding (here snow). The other options are wrong as at, by, and of indicate a specific location, usage, and possession respectively. These uses don't fit in the given question. The correct answer is D)in.