After Determining Whether the Variation Model Below Is of the Form

After determining whether the variation model below is of the form $y = k x \text { or }$
$\begin{array}{l}y = \frac { k } { x } \text {, find the value of } k\\\begin{array} { | l | l | l | l | l | l | } \hline x & 4 & 8 & 12 & 16 & 20 \\\hline y & \frac { 1 } { 6 } & \frac { 1 } { 12 } & \frac { 1 } { 18 } & \frac { 1 } { 24 } & \frac { 1 } { 30 } \\\hline\end{array}\end{array}$

A) $k = \frac { 1 } { 4 }$
B) $k = \frac { 3 } { 2 }$
C) $k = \frac { 5 } { 4 }$
D) $k = \frac { 1 } { 2 }$
E) $k = \frac { 2 } { 3 }$