Identify the most simplified version of the expression below: \[ \begin{array}{ll}\frac{\sqrt{2}}{\sqrt{18}} \\ \begin{array}{ll}\text { A) } \frac{\sqrt{3}}{3} & \text { C) } \frac{5 \sqrt{3}}{3} \\ \text { B) } \frac{1}{3} & \text { D) } \frac{3 \sqrt{2}}{3}\end{array}\end{array} \]

To simplify the expression \(\frac{\sqrt{2}}{\sqrt{18}}\), we can start by rewriting \(\sqrt{18}\): \[ \sqrt{18} = \sqrt{9 \cdot 2} = \sqrt{9} \cdot \sqrt{2} = 3\sqrt{2}. \] Now we can substitute this back into our expression: \[ \frac{\sqrt{2}}{\sqrt{18}} = \frac{\sqrt{2}}{3\sqrt{2}}. \] Next, we can simplify \(\frac{\sqrt{2}}{3\sqrt{2}}\): \[ \frac{\sqrt{2}}{3\sqrt{2}} = \frac{1}{3}. \] Thus, the most simplified version of the expression is: \[ \boxed{\frac{1}{3}}. \] This corresponds to option B.