Find a Linearization at a Suitably Chosen Integer near a at Which

Multiple Choice

Find a linearization at a suitably chosen integer near a at which the given function and its derivative are easy to evaluate.
- $$f ( x ) = \sqrt { x } , a = 9.1$$

A) $L ( x ) = \frac { 3 } { 2 } - \frac { 1 } { 6 } x$
B) $L ( x ) = \frac { 3 } { 2 } + \frac { 1 } { 3 } x$
C) $L ( x ) = \frac { 1 } { 2 } + \frac { 1 } { 2 } x$
D) $L ( x ) = \frac { 3 } { 2 } + \frac { 1 } { 6 } x$