Find the Slope of the Line That Goes Through the Given

Find the slope of the line that goes through the given points..
- $\left( \frac { 1 } { 2 } , 2 \right)$ and $\left( \frac { 1 } { 2 } , - 4 \right)$

A) Undefined
B) $- \frac { 4 } { 9 }$
C) $- \frac { 3 } { 4 }$
D) $- \frac { 4 } { 3 }$