Complex numbers $\mathrm{z}_{1}, \mathrm{z}_{2}, \mathrm{z}_{3}$ are the vertices $\mathrm{A}, \mathrm{B}, \mathrm{C}$ respectively of an isoceles right angled triangle right angled at $\mathrm{A} .$ Then, $\left(\mathrm{z}_{2}-\mathrm{z}_{3}\right)^{2}$ equals
(a) $2\left(z_{1}-z_{2}\right)\left(z_{1}-z_{3}\right)$
(b) $2\left(z_{2}-z_{1}\right)\left(z_{1}-z_{3}\right)$
(c) $3\left(z_{1}+z_{2}+z_{3}\right)$
(d) $\left(z_{2}-z_{1}\right)\left(z_{1}-z_{3}\right)$