The correct answer is option 2, Upagupta. Upagupta was a Buddhist monk who played a significant role in influencing Emperor Ashoka of the Maurya Empire to embrace Buddhism. Ashoka was initially involved in violent campaigns and conquests, but after witnessing the devastation caused by his actions, he regretted his past and sought spiritual guidance. It was Upagupta who helped Ashoka transform his life and become a devoted follower of Buddhism. Upagupta`s teachings and guidance had a profound impact on Ashoka`s beliefs and actions, leading him to promote non-violence, tolerance, and welfare activities throughout his empire. Upagupta`s influence was crucial in shaping Ashoka`s reign as a Buddhist emperor and his subsequent efforts to spread the teachings of Buddhism.