The length of the chord of the ellipse \( \dfrac{x^2}{25} + \dfrac{y^2}{16} = 1 \), whose mid-point is \( \left( 1, \dfrac{2}{5} \right) \), is equal to:
\( \dfrac{\sqrt{1741}}{5} \)
\( \dfrac{\sqrt{2009}}{5} \)
\( \dfrac{\sqrt{1691}}{5} \)
\( \dfrac{\sqrt{1541}}{5} \)