The correct answer is:
B. The Muslim domination of trade along the Indian Ocean.
Answer A is incorrect. Confucianism spread from China into Korea and from there to reached Japan already by the mid-6th century CE. Muhammad did not found the Muslim faith until the beginning of the 7th century CE, so simply on the basis of chronology that answer won't work. (There are other reasons answer A. is incongruous also -- just as answers C. and D. are unrelated to Muslim culture and the Arabian peninsula.)
Arab traders (from the centrally located Arabian peninsula)--who also had become Muslim followers of Mohammad's teachings--began to dominate the maritime trade routes along the Indian Ocean by the mid-7th century CE.