Answer
None of them are parallel or perpendicular.
Slopes are same for parallel lines. Slope of the line perpendicular to a line with slope $m$ is $-\frac{1}{m}$.
Since the slopes of line $a,b$ and $c$ doesn't meet the condition for parallel or perpendicular lines, none of the are parallel or perpendicular.
Work Step by Step
For line $a$, slope $m=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}=\frac{-1-(-4)}{-3-(-5)}=\frac{3}{2}$
For line $b$, $m=\frac{-6-(-4)}{-2-(-6)}=\frac{-2}{4}=-\frac{1}{2}$
For line $c$, $m=\frac{-1-(-6)}{0-(-3)}=\frac{5}{3}$
Slopes are same for parallel lines. Slope of the line perpendicular to a line with slope $m$ is $-\frac{1}{m}$.
Since the slopes of line $a,b$ and $c$ doesn't meet the condition for parallel or perpendicular lines, none of the are parallel or perpendicular.
