Respuesta :

Well, there isn't only one choice here - I'd say a coordinating conjunction is used in a complex and compound-complex sentence.
A coordinating conjunction gives equal emphasis to two (or more) main clauses - a simple sentence is only one main clause, as well as a compound sentence, which is why I wouldn't say those two answers are correct, but the remaining two should be.

Answer:

easy

Explanation:

Simple sentence—an independent clause that is a complete thought.   S+V

Compound sentence—contains two independent clauses linked by a comma and a coordinating conjunction; or linked by a semicolon.  

THE COORDINATING CONJUNCTIONS    and, but, or, for, nor, so, yet   Or a semi colon which indicates a longer pause than a comma but shorter than a period

Complex sentence—contains one independent clause and one or more subordinate clauses

Compound-complex sentence—contains at least one subordinate clause and at least two independent clauses.