An Elliptic Relation

Let there be an ellipse centred at the origin. Join a line from each focal point to an arbitrarily selected point (x,y). Let ${ l }_{ 1 }$ and ${ l }_{ 2 }$ be the lengths of each line. Find the correct expression for

$\left| { l }_{ 1 } - { l }_{ 2 } \right|.$

a) $e| x|/2$
b) $e| x|$
c) $2| x|/e$
d) $2 e | x|$

Note: e is the eccentricity of the ellipse.