Option 1: Baji Rai I - This is not the correct answer. Baji Rai I was a Maratha Peshwa who ruled from 1720 to 1740. He is not known as "Nana Saheb".

Option 2: Balaji Baji Rao - This is the correct answer. Balaji Baji Rao, also known as Nana Saheb, was a prominent Maratha ruler and the third Peshwa of the Maratha Empire. He ruled from 1740 to 1761 and played a crucial role in expanding the Maratha Empire and consolidating Maratha power.

Option 3: Balaji Vishwanath - This is not the correct answer. Balaji Vishwanath was the first Peshwa of the Maratha Empire and the father of Baji Rao I. He is not known as "Nana Saheb".

Option 4: Madhav Rao - This is not the correct answer. Madhav Rao was a later Peshwa of the Maratha Empire, ruling from 1761 to 1772. He is not known as "Nana Saheb".

In conclusion, the correct answer to the question is option 2, Balaji Baji Rao, who