the distance between W(-6,-8) and X(6,8) is given as follows,
[tex]WX=\sqrt[]{(8-(-8))^2+(6-(-6))^2}[/tex][tex]WX=\sqrt[]{(8+8)^2+(6+6)^2}[/tex][tex]\begin{gathered} WX=\sqrt[]{16^2+12^2} \\ WX=\sqrt[]{256+144} \\ WX=\sqrt[]{400}=20 \end{gathered}[/tex]now, the length is WX = 20, so the correct answer is option A.