A filled or half filled set of p- or d- orbitals is spherically symmetric. Point out the species which has spherically symmetry

 Na configuration is [Ne]3s¹       s orbital is half filled 
C configuration is 1s² 2s² 2p²     p orbital is not half filled and full filled
Cl^- configuration is 1s² 2s² 2p⁵ 3s²     p orbital is not half filled and full filled
Fe configuration is [Ar]3d⁶ 4s²       d orbital is not half filled and full filled
Therefore,  Na is spherically symmetric