Explanation:

- Chandrabhan Brahman: He was a Persian-language poet and scholar during the Mughal era. Chandrabhan Brahman is credited with writing 'Char Chaman,' a book that provides insight into the Mughal nobility during Shah Jahan's reign. Correct Answer: Chandrabhan Brahman.

- Abu’l Fazl: He was a court historian and close advisor to Akbar, Shah Jahan's grandfather. Abu’l Fazl is best known for writing the 'Akbarnama,' the official history of Akbar's reign, not Shah Jahan’s era.

- Muhammad Waris: A historian who was associated with the Mughal court. Although he documented Mughal history, he is known for continuing work on the 'Padshahnama,' which was initiated during Shah Jahan's reign.

- Gulbadan Begum: She was a Mughal princess and author of 'Humayun-nama,' a historical account of her brother Humayun, not Shah Jahan's reign. Her work provides valuable insights into the Mughal family but does not focus on Shah Jahan’s nobility.

The correct answer is Chandrabhan Brahman.