If the points $\mathrm{z}, \mathrm{i} z,(\mathrm{z}-\mathrm{i} z)$ represent the vertices of a triangle in the Argand plane, then,
(a) area of the triangle $=\frac{1}{2}|\mathrm{z}|^{2}$
(b) orthocenter is at $(1-\mathrm{i}) \mathrm{z}$
(c) circumcentre is at $\frac{1}{2}(1-i) z$
(d) centroid is at the origin