The answer to the question stated above would be letter b) The Himalayas protect the crops of Indian farmers from heavy rains and extreme weather. Geography affects the economic activity in South Asia (specifically in India) because of the Himalayas that protect the farmlands from extreme weather conditions.
That's false.
The definition cited above is related to "Economy".
The real definition of Ecology can be expressed by the "science that studies the relationships of living beings to each other or to the organic or inorganic environment in which they live also, the moral, social and economic aspects".
They were able to stay isolated from the world for so long because of the way there were on the map
I think the answer is residual phase. It's the final stage of schizophrenia. :)