The correct answer is D. Compound-complex sentence
Explanation:
Complex sentences different from simple or compound sentences always include a dependent clause connected to an independent clause. In the case of the sentence presented "Before the car wash" is the dependent clause because this does not express a complete idea and includes the word "before" that is a subordinating conjunction and "Tanya made signs and Gabe signed up volunteers" is the independent clause as this expresses a complete thought. Besides this, a sentence is compound if two ideas of the same importance are included and joined by a conjunction such as and, or, but, which occurs in "Tanya made signs and Gabe signed up volunteers". This means the sentence includes the elements of a complex sentence (independent-dependent clause) and a compound sentence (two independent clauses) and therefore it is a compound-complex sentence.
Why did the neighbours immediately call the cops? Did they already know he was guilty? Were the cops making him go insane at the end? Did the cops suspect him before he admitted it? What is wrong with the narrator mentally? Is he even human?