Answer: compound
Explanation: Simple sentences: A simple sentence is an independent clause with no conjunction or dependent clause.
Compound sentences: A compound sentence is two independent clauses joined by a conjunction (e.g., and, but, or, for, nor, yet, so).
Complex sentences: A complex sentence contains one independent clause and at least one dependent clause. The clauses in a complex sentence are combined with conjunctions and subordinators, terms that help the dependent clauses relate to the independent clause. Subordinators can refer to the subject (who, which), the sequence/time (since, while), or the causal elements (because, if) of the independent clause.
Compound-complex sentences: A compound-complex sentence contains multiple independent clauses and at least one dependent clause. These sentences will contain both conjunctions and subordinators.