Sulfur has two filled energy levels and six electrons on the third energy level. The corresponding electron configuration is A. B is incorrect because there are no p orbitals at the first energy level, ie, no 1p orbitals. C is incorrect because the 4s1 electron would spontaneously drop into the 3p orbitals. D is incorrect because the 3d electrons would spontaneously drop into the 3p orbitals.