The original name of district Unnao was:

Correct option is A

The correct answer is (a) Sawai Godo
Explanation: . According to historical records and local traditions, the site of the present-day Unnao town was covered by extensive forests about 900-1200 years ago. . A Chauhan Rajput, Godo Singh, cleared the forests in the third quarter of the 12th century and founded a town. . This original town was named  Sawai Godo after himself. . Later, a Bisen Rajput lieutenant of the Kannauj governor, Unwant Rai Singh, took over the area, built a fort, and renamed the place Unnao after himself. 
Information Booster: . The British established the district after annexing Oudh (Awadh) in 1856, initially calling it "Purwa district" with headquarters at Purwa. . The headquarters were soon shifted to Unnao due to its central location, and the district was formally named District Unnao after the headquarters city. . The district is situated between the Ganga and Sai rivers and is known historically as the "land of pen and sword". 
Additional Knowledge: Satyavadi (Option b) . This name is not historically associated with the origin of Unnao district. The word means 'truth-teller' and relates to various figures in Indian mythology, like King Harishchandra.
Vishnupur (Option c) . This name is not historically linked to Unnao's origin. It generally translates to 'City of Vishnu' and refers to several other locations in India.
Pratap Nagar (Option d) . This name is not the original name of Unnao. Pratap Nagar is a common place name in various cities in India.