The correct answer is Sher Shah Suri.
Sher Shah Suri was a Pashtun warrior who founded the Suri dynasty in the Indian subcontinent. He was the first Muslim ruler to defeat the Mughal Empire and capture the Mughal capital of Agra. He is also credited with building the Rohtas Fort, which is located in the Punjab province of Pakistan.
The Rohtas Fort is a massive fort that was built to defend against the Mughal Empire. It is one of the largest forts in the world and is considered to be one of the finest examples of military architecture in the Indian subcontinent.
Akbar was the third Mughal emperor. He was a great military leader and expanded the Mughal Empire to its greatest extent. He is also known for his religious tolerance and his patronage of the arts.
Qutubuddin Aibak was the first Sultan of Delhi. He was a Turkic slave who came to India with Muhammad Ghori. He founded the Mamluk dynasty in India.
Humayun was the second Mughal emperor. He was the son of Babur, the founder of the Mughal Empire. He was defeated by Sher Shah Suri and fled to Persia. He later returned to India and recaptured the Mughal throne.
In conclusion, the correct answer to the question “The famous Rohtas Fort was constructed as a defense by:” is Sher Shah Suri.