In Solid Sodium Metal, Which Orbital(s)contribute(s)to the Formation of the Delocalized

In solid sodium metal, which orbital(s) contribute(s) to the formation of the delocalized band of energy levels?

A) 3s
B) 1s, 2s
C) 1s, 2s, 3s
D) 1s, 2s, 2p
E) 1s, 2s, 2p, 3s