Answer:
C
Step-by-step explanation:
Complex sentences have one or more dependent (sometimes called subordinate) clauses. A dependent clause is a part of a sentence that would not make sense or would be incomplete by itself. B is an example of a complex sentence, because it has both an independent (I read an old magazine) and a dependent clause (As I waited for my appointment). C is not a complex sentence because it is made up of one independent clause. Hope this helps a little! :)