Something that is simultaneously itself and a sign of something else

Something that is simultaneously itself and a sign of something else is called "Symbol".
For example darkness, coldness or silence is in themselves something but in a literary world they are also used as the symbol for death. Or like warmth, it in itself is something but represents life also in literature. 

even though you have attached neither the chart nor the generalizations, i have located them online. the right answer is d, since they are asking you about a generalization. you can only infer from the chart that between 2008 and 2009 the number of employed workers decreased significantly (from over 115 millions to 107 millions approximately), which signals some type of economic crisis.  

answer; ///associate's degree;