<p dir="ltr"><span><span>The question is a complex sentence. The main clause is “The manager believes something,” followed by a noun clause that starts with the subordinating conjunction “that” and continues to the end of the question to explain what is believed by the manager. </span></span></p><p dir="ltr"><span><span>Let’s focus on the noun clause “that by the end of this month, all of the office renovations ________ completed.” The blank should be filled with a verb for this noun clause. All the four choices are possible answers since they are all variations of a be verb. </span></span></p><p dir="ltr"><span><span>The key to identifying the correct answer is figure out whether the be verb is used in the correct tense. The phrase “by the end of this month” suggests that the verb for this noun clause should be in the future tense. For this reason, Choice (D) </span><span>will have been</span><span> is the correct answer since it’s in the future perfect tense. </span></span></p><p dir="ltr"><span><span>Choice (A) </span><span>was being</span><span> is incorrect because it’s in the past continuous tense. </span></span></p><p dir="ltr"><span><span>Choice (B) </span><span>has been</span><span> is incorrect because it’s in the present perfect tense. </span></span></p><p dir="ltr"><span><span>Choice (C) </span><span>is being </span><span>is incorrect because it’s in the present continuous tense.</span></span><br></p>