Two numbers x and y (x > y) are such that their sum is equal to three times their difference. Then value of $\frac{3xy}{2\left ( x^{2} - y^{2} \right )}$ will be :
[A] $1\\frac{2}{3}$
[B] 1
[C] $\\frac{2}{3}$
[D] $1\\frac{1}{2}$