Consider the vector $u=($:$-2,1,-3$:$)$

$($a$)(2$ pts$)$ Which of the following vector is parallel to $u.$

i$.($:$-4,2,-6$:$)$

ii$.($:$-6,2,-9$:$)$

iii. $($:$-3,2,-1$:$)$

$($b$)(2$ pts$)$ Which of the following vector is perpendicular to $u.$

i$.($:$3,2,4$:$)$

ii$.($:$2,1,1$:$)$

iii. $($:$3,0,-2$:$)$