The Chinese introduced Buddhism to Korea. Option A is correct.
Chinese Buddhism or Han Buddhism, has developed Chinese culture in a wide range of fields such as art, politics, literature, philosophy, medicine and material culture.
Korean Buddhism is different from other forms of Buddhism by its attempt to resolve what it considers as inconsistencies in Mahayana Buddhism. Korean Buddhism has contributed much to East Asian Buddhism, particularly to early Chinese, Japanese, and Tibetan schools of Buddhist thought.
