The correct answer is: Ashoka.
Ashoka the Great was the third emperor of the Mauryan Empire in India. He ruled from 272 to 232 BCE and is considered one of the greatest rulers in Indian history. Ashoka was a devout Buddhist and he is credited with spreading Buddhism throughout the Indian subcontinent and beyond. He sent Buddhist missionaries to many parts of Asia, including the Himalayan states.
Majjhima was a Buddhist monk who lived in the 6th century BCE. He was one of the disciples of the Buddha and he is considered one of the founders of the Theravada school of Buddhism. Majjhima is not known to have preached Buddhism in the Himalayan states.
Bindusar was the second emperor of the Mauryan Empire. He ruled from 297 to 272 BCE. Bindusar was a Hindu and he is not known to have preached Buddhism in the Himalayan states.
Bimbisar was the first emperor of the Mauryan Empire. He ruled from 322 to 297 BCE. Bimbisar was a Hindu and he is not known to have preached Buddhism in the Himalayan states.
In conclusion, Ashoka is the only person among the options who is known to have preached Buddhism in the Himalayan states. Therefore, he is the correct answer to the question.