The Treaty of Bassein was signed in 1802 between the British and Baji Rao II. Baji Rao II was the last Peshwa ruler of the Maratha Empire. The Marathas were a major power in India during the 18th century, and the Peshwas were appointed as the chief ministers of the Maratha Empire.

In the late 18th century, the Marathas faced numerous internal conflicts and also had to deal with the threat from the British East India Company. Baji Rao II sought British assistance to maintain his power and control over the Maratha Empire. The Treaty of Bassein was a result of this collaboration between Baji Rao II and the British.

By signing the treaty, Baji Rao II accepted British intervention in Maratha affairs and agreed to defend the British territories in India. The treaty also required the Marathas to disband their armies and accept British advisors in their administration. Essentially, the Treaty of Bassein marked the beginning of British dominance over the Maratha Empire.

Overall, option 2 (Baji Rao II and the British) is the correct answer.