Two chords AB and CD of a circle intersect each other at a point E, inside the circle. If $AE= 3\;cm,CE=5\;cm$ and $EB= 4\;cm$, then $ED= $ __________

Question

$\begin{array}{1 1} 2.5\;cm \\ 2.4\;cm \\2.3\;cm \\2\;cm \end{array} $