They can't join the army or go to school.The can play sports.
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.
It's, "We hold these truths to be self-evident "that all men are created equal, that they are endowed "by their Creator with certain unalienable Rights, "that among these are Life, Liberty, and the pursuit "of Happiness.
I believe your answer is A. Hope this helps!!
-K
I uploaded the answer to a file hosting. Here's link:
tinyurl.com/wpazsebu