I believe that this is a Subordinate clause.
1) "Because" is a subordinate conjunction.
2) "Because there was two feet of snow", can not stand on its own. It depends on the main clause, "school was cancelled to today".
I hope this helped! :)
Answer:
past perfect is the answeer
The last one because it is giving vivid imagery. There are descriptive adjectives in the sentence as well, that tells the reader what kind or quality of the noun.