How many integers n≥2 are there such that whenever z1,z2,...,zn are complex numbers such that
∣z1∣=∣z2∣=...=∣zn∣=1 and z1+z2+...+zn=0,
then the numbers z1,z2,...,zn are equally spaced on the unit circle in the complex plane?<spanclass=′latex−bold′>(A)</span>1<spanclass=′latex−bold′>(B)</span>2<spanclass=′latex−bold′>(C)</span>3<spanclass=′latex−bold′>(D)</span>4<spanclass=′latex−bold′>(E)</span>5