Why are some countries in oceania often grouped with southeast asia?

a: sotheast asia wants to control as much land as possible.

b: the climate of southeast asia is very similar to western australia

c: there is a common language spoken throughout oceania

d: northern countries in oceania have more in common with southeast asia

D: Northern countries in Oceania have more in common with Southeast Asia

Explanation:

   Southeast Asia is made up of: Brunei, Cambodia, the Philippines, Indonesia, Laos, Malaysia, Myanmar, Singapore, Thailand, Timor-Leste and Vietnam.

   Indonesia is considered a transcontinental country, located between Southeast Asia and Australia, so for some it is also considered a nation of Oceania.