Упростите выражение \(\frac{4m^2}{2m-n}\div\frac{12m^3}{4m^2-n^2}\cdot\frac{2m^3}{6m^2+3mn}\) .
\(\frac{2m}{9}\)
\(\frac{2m^2n}{9+9n}\)
\(\frac{2n}{9+9n}\)
\(\frac{2n}{1+n}\)