Answer: In order to demonstrate that one idea is less important than another, Bernice will use a (A.) complex sentence.
Step-by-step explanation: A complex sentence is a sentence made up of an independent clause and at least one dependent clause. While an independent clause can stand alone as a sentence because it makes reference to a complete idea, a dependent clause cannot stand by itself because it does not express a full thought. Moreover, a dependent clause is always introduced by a subordinating conjunction. In that way, Bernice could use a complex sentence to demonstrate that one idea (the one expressed in the dependent clause) is less important than another one (the one expressed in the independent clause).