The three vertices of a triangle are represented by the complex numbers $0, z_{1}$ and $z_{2}$. If the triangle is equilateral, then
(A) $z_{1}^{2}+z_{2}^{2}+z_{1} z_{2}=0$
(B) $z_{1}^{2}+z_{2}^{2}=z_{1} z_{2}$
(C) $z_{2}^{2}-z_{1}^{2}=z_{1} z_{2}$
(D) $z_{1}^{2}-z_{2}^{2}=z_{1} z_{2}$