The correct answer is: D. hasn’t told/won’t be coming
The sentence is in the present perfect continuous tense, which is used to talk about actions that started in the past and are still happening now, or actions that have just happened. The past participle of “tell” is “told,” and the past participle of “come” is “come.”
In this sentence, the subject is “he,” and the verb is “hasn’t told.” The direct object is “his boss,” and the indirect object is “that he is coming back after his vacation.”
The sentence can be paraphrased as follows: “He has not told his boss that he is coming back after his vacation.” This means that he has not yet told his boss that he is coming back, but he plans to do so in the future.
The other options are incorrect because they do not agree with the tense of the sentence. Option A, “doesn’t tell/hasn’t come,” is in the present simple tense, which is used to talk about general truths or habits. Option B, “won’t tell/won’t have come,” is in the future perfect tense, which is used to talk about actions that will have happened by a specific time in the future. Option C, “isn’t telling/doesn’t come,” is in the present continuous tense, which is used to talk about actions that are happening now. Option E, “didn’t tell/hadn’t come,” is in the past simple tense, which is used to talk about actions that happened in the past.