The correct answer in my opinion would be that D is the most important factor here. But this question is quite tricky.
We can surely say for example that literature, organized schools and a hierarchy of priests are not something that constitute a civilization. Organized schools appeared to late, not every civilization had literature and having only a hierachy of priests is not enough to say you have a civilizaton.
Labor has been divided in pre-civilization hunter-gatherer societies as well. 
For that reason I'd say the correct answer is D - more food than is needed for survival. Having this, the people in a certain group can focus on other things. 
        
             
        
        
        
Hernan Cortés is the answer. 
 
        
                    
             
        
        
        
The framers of the Constitution devised a system wherein no one branch of the Government would be able to dominate.
This means that, by design, each branch of the US Federal system is co-equal.
This ensures that before action is done on behalf of the people of the US by the Federal government, there are adequate safeguards to ensure that what is being done is done within the bounds of the Constitution. 
 
        
             
        
        
        
Assuming that you're referring to President Roosevelt, i think he believed that the government could best bring social and economic change.
This proved by his action when he signed the New Deal to handle the horrific depression in our coutnry
        
             
        
        
        
The winds of revolution sweeping Egypt today aren’t the first that have ravaged that nation.
Most history textbooks open with a description of ancient Egypt as a towering civilization that, for more than a millennium, led mankind’s intellectual, political and cultural advancement. Each year, millions of visitors marvel at the pyramids jutting from Egypt’s dunes, at the mummified remains of the ancient pharaohs, and at Egypt’s mountains of other artifacts and relics—all testimony to the power the civilization once held.
But perhaps the most striking facet of Egyptian history is its precipitous fall.
Modern-day Egyptians, after all, are not descended from those ancient societies that constructed the Giza Pyramid Complex, the Great Sphinx, and other momentous structures. They have no connection to the early dynastic peoples that pioneered new frontiers in science, mathematics and art, and that once dominated the civilized world. Today’s Egypt is inhabited and ruled by Arabs; before that it was under British control; before that it was controlled by various Muslim peoples, including the Ottomans; before that it was the Romans; before that the Greeks; and before that the Persians.
Egypt has resurfaced intermittently in the past 2,500 years of world history,but always as the territory of a foreign nation or empire. What happened toancient Egypt—the unique and independent civilization established by the pharaohs, the nation that once reigned over mankind? That Egypt has clearly vanished.