Concept:A dative bond is a covalent bond where both shared electrons come from one atom.Explanation:Ammonia (NH3) has a lone pair of electrons on nitrogen.The hydrogen ion (H+) has no electrons of its own.Nitrogen donates its lone pair to form the ammonium ion (NH4+).This shared pair creates a coordinate covalent bond, also called a dative bond.Answer:B. Dative