Answer:
Compound-complex.
Explanation:
Compound-complex sentences are the types of sentences that contains one dependent clause and two independent clauses. Compound-complex sentences contains of compound as well as complex sentences.
This type of sentence is used to express the thoughts that are usually long and complicated.
In the given question, the dependent clause is "As cold weather approaches..." and the two independent clauses are "you must protect your water pipes against freezing..." and "or they can rupture and cause significant damage to your home."
So, the correct answer is compound-complex sentences.
