the population in east asia is concentrated in:

a. urban areas, river valleys, and coastal
b. japan, korea, and mongolia
c. the southern and western regions of china
d. urban areas only
my answer b.

I would say a.

No.

http://maps.howstuffworks.com/asia-population-density-map.htm

As you can see from the map, Mongolia is sparsely populated.

Mongolia is also not in East Asia. Neither are "western regions of China".

oh ok thank you both

To determine the correct answer, we need to understand the geography and population distribution of East Asia.

East Asia consists of countries such as China, Japan, South Korea, North Korea, Mongolia, and Taiwan. Now, let's evaluate each option:

a. Urban areas, river valleys, and coastal: This option seems plausible as urban areas, river valleys, and coastal regions are often highly populated due to economic opportunities and access to resources.

b. Japan, Korea, and Mongolia: This option does not accurately represent the entire population distribution in East Asia as it only includes Japan, Korea, and Mongolia, leaving out other significant countries in the region.

c. The southern and western regions of China: This option is also not entirely correct as it only refers to specific regions within China, omitting other countries in East Asia.

d. Urban areas only: This option restricts the population concentration to urban areas alone, which does not capture the complete picture of East Asia's population distribution.

Considering the explanations above, the correct answer is a. Urban areas, river valleys, and coastal. These areas tend to have higher population density due to better access to resources, transportation networks, and economic opportunities.