The correct answer is D. Gulbadan Begum.
Gulbadan Begum was the daughter of Babur, the founder of the Mughal Empire, and his wife Maham Anga. She was a prolific writer and is best known for her memoirs, the Humayun Nama, which chronicles the life of her father.
The Humayun Nama is an important historical document that provides insights into the early Mughal Empire. It is also a valuable source of information about the life of Gulbadan Begum herself.
The other options are incorrect.
A. Humayun was the subject of the Humayun Nama, not the author.
B. Mirza Kamran was Humayun’s brother. He was a rival to Humayun for the Mughal throne and is not known to have written any memoirs.
C. Bairam Khan was a general and regent for Humayun. He is not known to have written any memoirs.