The correct option is C. Shark attacks are rare, and attacks can be prevented if swimmers are careful.
A compound-complex sentence brings both of these sentence forms together. In other words, ia compund-complex sentence contains at least two independent clauses (like a compound sentence) and at least one dependent clause (like a complex sentence). A complex sentense consists on a dependent clause joined to an independent clause. And a compound sentences are formed by combining two independent clauses.
