How old do you have to be to join the police academy?

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.  

i believe the answer is: description

description refers to the goal of psychologist to identify the phenomenon that being observed. this goal is being actualized by collecting data/information from various clues that observed through the phenomenon. this goal must be accomplished before pyschologist able to create methods of treatment.