Final answer:
When electrons in a bond are closer to one atom, it's a polar covalent bond due to unequal sharing of electrons influenced by differences in electronegativity.
Step-by-step explanation:
If electrons involved in bonding spend most of the time closer to one atom rather than the other, the bond is a polar covalent bond. A polar covalent bond is one where the bonding electrons are shared unequally between the two atoms, with the electron density being greater around the more electronegative atom. This can happen when the electronegativity difference between the two atoms is between 0.5 to 1.9. Therefore, out of the given options, the correct answer is: 3) Polar covalent.