A molecule or ion that donates the hydrogen in a hydrogen bond is a hydrogen bond donor A molecule or ion that binds to this hydrogen is a hydrogen bond acceptor. Specify the hydrogen bonding behavior of the 4 species below by selecting: donor for species that act as donors only acceptor for species that act as acceptors only both for species that act as both donors and acceptors neither for species that act neither as donors nor as acceptors.

The question is incomplete, the complete question is found in the image attached.

1- acceptor

2-donor

3-acceptor

4-donor

Explanation:

A hydrogen bond acceptor is a molecule that has an electronegative atom having a lone pair of electrons that participates in the hydrogen bond.

A hydrogen bond donor is the molecule that supplies the hydrogen atom of a hydrogen bond.

If we look at structure I-IV in the image attached, I and III are hydrogen bond acceptors because they all possess electronegative atoms having lone pairs of electrons but do not have hydrgen atoms bonded to highly electronegative atoms.

Similarly, structures II and IV are hydrogen bond donors. The C=C double bond is electron withdrawing and highly electronegative making the hydrogen atoms attached to it acidic and hydrogen bond donors. Also, nitrogen is an electronegative atom thereby making structure IV a hydrogen bond donor.

the answer is c. nacl