Which of the following explains the spatial patterns of economic development for most countries in Southeast Asia, including Indonesia, Malaysia, Thailand, and Vietnam?

a
Most Southeast Asian countries are considered to be part of the core because of the dominance of the tertiary economic sector.
b
Most Southeast Asian countries are considered to be part of the periphery because of the dominance of the tertiary economic sector.
c
Most Southeast Asian countries are considered to be part of the semiperiphery because of the dominance of the primary economic sector.
d
Most Southeast Asian countries are considered to be part of the semiperiphery because of the extensive growth of the secondary economic sector.
e
Most Southeast Asian countries are considered to be part of the periphery because of the dominance of the secondary economic sector.