What is the basis of a metallic bond?

A. the attraction of metal ions for mobile electrons

B. the attraction between neutral metal atoms

C. the neutralization of protons by electrons

D. the attraction of oppositely-charged ions

The correct option is A. The attraction of metal ions for mobile electrons

Formation of metallic bond:

In metals, the valence shells electrons of s and p orbitals are mostly delocalized forming sea of electrons. These free electrons surround the positively charged atoms resulting formation of metallic bonding.

The attraction of metal ions for mobile electrons