First place to come up with and practice democracy ancient Greece
Migration led to the population of the world because human life started in Africa, meaning that for people to inhabit places that are now known as America, Europe, Australia, etc., they had to all migrate out of Africa.
D: They sought a more hospitable climate :-)
The answer is potatoes and maize
I beleive your answer is D it was one of the most fortified islands in the island hopping campaign.