The Cost (In Dollars) of Producing $x$ Units of a Certain Commodity Is

The cost (in dollars) of producing $x$ units of a certain commodity is
$$C ( x ) = 4,280 + 13 x + 0.03 x ^ { 2 }$$
Find the average rate of change with respect to $x$ when the production level is changed from $x = 102$ to $x = 122$ .

A) $23.02$
B) $14.42$
C) $29.94$
D) $16.42$
E) $19.72$