[单选题]
Covalent bonding is causebfn p5 )1,bqelvwuz.6da ol0 ;7i0we3s 0dpgt4pu(sfeu 7o2rq by
A. the sharing of electrons between atoms.
B. the transfer of electrons between atoms.
C. unequal charge distributions around neutral molecules.
D. atoms bonding to hydrogen molecules.