Find the Limit as X Approaches C of the Average $$f ( x ) = \frac { x } { 3 } + 10$$

Multiple Choice

Find the limit as x approaches c of the average rate of change of the function from c to x.
-c = 9; $$f ( x ) = \frac { x } { 3 } + 10$$

A) 3
B) Does not exist
C) 13
D) $$\frac { 1 } { 3 }$$