It would be much easier to help you if you mentioned what's the name of the story. Anyway, I think I've got what you mean. I hope you will find it helpful.
Here are the answers:
1. C.) Blackie<span> was the original leader of the gang.
2. The </span>C.) staircase<span> stuck up like a jagged tooth.
3. The gang’s plans for the day were decided by </span>B.) a vote.
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Sorry if something is wrong. In my view all of them are correct.
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I'm pretty sure it's B- painful
a sentence containing a subordinate clause or clauses or you can also say its a complex sentence contains an independent clause and at least one dependent clause.
Answer:
Authors usually write texts to get their point across or teach the reader a lesson. (could you provide the text for a better answer please)
Hope this helped :)