\(LCD: 6
\\\frac{1}{2}* \frac{3}{3} = \frac{3}{6}
\\\\\frac{1}{3}*\frac{2}{2} = \frac{2}{6}
\\To \ Find \ Seth's \ Amount \ , \ Add \ These \ Two \ And \ Subtract \ From
\\The \ Whole
\\\\\frac{2}{6} + \frac{3}{6} = \frac{5}{6}, \frac{6}{6}-\frac{5}{6} = \frac{1}{6}
\\Seth \ Got \ 1/6 \ Of \ The \ Sandwich
\\ The \ Ratio \ Is \ 3:2:1
\\\boxed{answer \ choice \ D}\)
