Emily is doing a research project about hiking. which topic would give her the best and most useful information about hiking?

If its a USATesPrep Question then the answer should be  

A) what gear is needed for a long hike

Full question

Emily is doing a research project about hiking. Which topic would give her the best and most useful information about hiking?

A) what gear is needed for a long hike

B) different kinds of healthy snacks

C) the most popular outdoor sports

D) a list of types of rocks

elastic potential energy

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.