Estimate the Derivative of the Function $f ( x ) = \frac { x ^ { 2 } } { 8 } - \frac { x ^ { 3 } } { 6 }$

Multiple Choice

Estimate the derivative of the function $f ( x ) = \frac { x ^ { 2 } } { 8 } - \frac { x ^ { 3 } } { 6 }$ at the point $x = - 2$ .
Please select the correct answer rounded to the nearest hundredth.

A) -2.5
B) -2.55
C) -3
D) -0.5
E) -2.45