Which plebeian marriage ritual symbolizes the purchase of the bride?

The correct answer is coemptio. This plebeian marriage ritual involves a symbolic transaction or purchase of the bride. In this ceremony, the groom would pretend to buy the bride, and this act signified a transfer of authority and responsibility from the bride's family to the groom. The ritual served both as a formalization of marital union and a recognition of the economic and social bonds formed between the families involved.

Ius primae noctis, often mythologized in popular culture, refers to the supposed right of a lord to sleep with a subordinate's bride on her wedding night but does not pertain to the marriage ritual itself. Confarreatio is a distinct, ancient Roman wedding ceremony involving the sharing of a special cake and is generally associated with patrician marriages rather than plebeian ones. Usus, another form of marriage, could involve cohabitation and is characterized by a different approach to marital legitimacy and property rights, rather than the explicit symbolic purchase that occurs in coemptio.