The Rohtas Fort, one of the strongest medieval forts in India, was built by which ruler?

The wording of the question specifically requires the association represented by Sher Shah Suri. Option A (Akbar) is incorrect because it does not match the specific person, district, place, institution, event or factual association asked in the question. Option B (Humayun) is incorrect because it does not match the specific person, district, place, institution, event or factual association asked in the question. Option D (Aurangzeb) is incorrect because it does not match the specific person, district, place, institution, event or factual association asked in the question. The Rohtas Fort (Rohtasgarh) in Rohtas district of Bihar was built by Sher Shah Suri, the Afghan ruler who temporarily displaced Mughal emperor Humayun from the throne of India. Sher Shah Suri (born Farid Khan) was born in Sasaram, Bihar (also in Rohtas district), and became one of the most capable administrators in Indian history. The Rohtas Fort is situated on a plateau in the Kaimur hills and is considered virtually impregnable due to its natural defenses and strategic location. It was also used by Humayun during his campaigns against Sher Shah. Akbar was the third Mughal emperor who built magnificent forts like Agra Fort and Fatehpur Sikri, but not Rohtas Fort. Humayun was the second Mughal emperor who was ousted by Sher Shah. Aurangzeb was the sixth Mughal emperor, known for Bibi ka Maqbara, not Rohtas. The Rohtas Fort is an ASI-protected monument and a heritage site of significant historical importance.