The correct answer is d. hunting -gathering.
Hunting and gathering was already existing before this : in fact the neolithic revolution was going away from this lifestyle and starting farming and domestication of animals.
The correct answer to this open question is the following.
I think the Candy Bomber reflects the story of the Berlin Airlift in that it shows the humanitarian side of the military, in this case, American Colonel Gail Halvorsen, who was a command pilot for the US Airforce that participated in the Berlin Airlift, after Soviet leader Joseph Stalin had ordered to close any land entries to West Berlin.
Colonel Halvorsen used to drop candy as a gift to German kids. So people started to call him "Candy Bomber."
The United States, France, and British Airforce sent airplanes full of food and supplies to West Berlin. This helped people survive for almost a year.
That would be the principal of federalism
The best description in terms of how a parliamentary democracy differs from a presidential democracy would be that "<span>C) In a presidential democracy, political power is shared between state and federal governments," since in a Parliamentary government it is more based on districts. </span>
