The answer is:  [A]:   "  aₙ = n – 2 " .
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  Explanation:   "aₙ" represents "y" on the "y-axis". 
                      
                         "n" represents "x" on the "x-axis".
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         Considering the answer choices given, one can look at the graph.  When one looks at the graph, when "x = 2, y =0 " ;  or,  when "n = 2, aₙ = 0 ".
   When examining the answer choices, we see that "{Answer choice: [A]" } is the ONLY equation given when these values fit.  Furthermore, by plugging in a few more values on the line, we see that the "equation" in 
"{Answer choice [A] }" makes sense.
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