He will be writing some letters tomorrow morning.
There is no passive voice transformation for Future Continuous Tense. Hence option D is the answer.
940 MCQ for effective preparation of the test of Voices of English Grammar section.
Read the MCQ statement: He will be writing some letters tomorrow morning. , keenly and apply the method you have learn through the video lessons for Voices to give the answer. Record your answer and check its correct answer and video explanation for MCQ No. 59-4338.