Change voice: He is writing a book.

by

(A) A book has been written by him.
(B) A book is being written by him.
(C) A book was being written by him.
(D) None of these

🧠 Explanation:

  • The sentence is in present continuous tense: "is writing."
  • To change into passive voice, use "is being" + past participle.
  • "A book is being written by him" follows the correct structure.
  • The focus shifts from the subject "he" to the object "a book."