Estimate the Slope of the Line Segment $m = 0$ B) $m = - \frac { 1 } { 2 }$

Estimate the slope of the line segment.

A) $m = 0$
B) $m = - \frac { 1 } { 2 }$
C) $m = y$
D) $m = \frac { 1 } { 2 }$
E) Undefined