Although it was raining, sheila stopped to the puppy who had fallen into the deep hole.
what is the structure of this sentence?
a) complex
b) compound
c) compound-complex
d) simple
explain it so i can understand.

The structure of above sentence is complex.  

Option A

Explanation:

When a sentence consists one independent clause and one or more subordinate clause is said to be a complex sentence. In the above sentence, ''Sheila stopped to help the puppy'' is the independent clause which can form a simple sentence by itself. ''Although it was raining and who had fallen into the deep hole'' are the dependent clauses that does not form a simple sentence by itself.

These two clauses connected by relative pronouns or adverbs are the examples of complex sentences. We can combine them together to get a complex sentence.

to give the reader a sense of the chaos, fear, and havoc taking place

choice 2 i like that prompt better.