Find a Unit Vector in the Direction of the Given $\left[ \begin{array} { r } 13 \\ - 26 \end{array} \right]$

Multiple Choice

Find a unit vector in the direction of the given vector.
- $\left[ \begin{array} { r } 13 \\ - 26 \end{array} \right]$

A)
$\left[\begin{array}{l}\frac{1}{\sqrt{5}} \\\frac{2}{\sqrt{5}}\end{array}\right]$

B)
$\left[\begin{array}{c}\frac{1}{\sqrt{5}} \\-\frac{2}{\sqrt{5}}\end{array}\right]$

C)
$\left[\begin{array}{c}\frac{1}{\sqrt{3}} \\-\frac{2}{\sqrt{3}}\end{array}\right]$

D)
$\left[\begin{array}{r}\frac{1}{5} \\-\frac{2}{5}\end{array}\right]$