Answer: A. Since the beginning of recorded history, the region has been multiethnic.
Southeast Asia has been the home of many different ethnic groups since the beginning of recorded history. The Aslians and Negritos (related to Papuans and Australians Aborigines) are believed to have been the first people in the region, followed by Austroasiatic and Austronesians.
In modern times, the ethnic groups of the region include the Javanese (largest group in the region), the Vietnamese, the Thais, the Burmese, the Sundanese, the Madurese, the Minangkabau, the Bugis, the Balinese, the Dayak, the Batak, the Tagalog and the Malays.
