Which is the primary reason that the australian population is clustered around its major cities? the economy of the country is dominated by industry. the inland region is mountainous terrain that is too difficult to inhabit. people settle in the areas with the mildest climates, and this is where most of the cities then developed.

I believe the answer is C) People settle in the areas with the mildest climates, and this is where most of the cities then develop. 
Australia is covered with deserts, tropical jungles, and grasslands. The most population is set up in the places that best support human development. 
Hope this helps! Please let me know if I'm wrong :) 

Answerwill have thinner; have thicker oceanic sediments;