A semicolon separates two related independent clauses. There are two independent clauses in the sentence: "My parents are cleaning the house today" and "that means we must be expecting company." This means there should be a semicolon in the sentence. It would go after the word "house," because that is where the first clause ands and the second begins. Therefore, the answer is D. house.
Whenever you're leaving a phone message, you should speak clearly, spell your name, state your purpose, and: C. Leave your phone number. That is the professional way. Hope that helps.
