Most of the land of Southeast Asia is

Abelow sea level, so a system of dikes is used to keeping it from flooding.
Bcontained in a vast land mass with very few bodies of water.
Csubject to a desert-like climate.
Deither part of a peninsula or part of an archipelago.

Verified Answer :

the correct what is the last one.

Southeast Asia can be roughly divided into the Mainland Southeast Asia- that's the peninsula with Cambodia, Laos and other countries, and into the Maritime Southeast Asia- the Malay Archipelago or East-Indies( historical name).