खालीलपैकी कोणत्या बाजारपेठेत एखाद्या उत्पादन/सेवेसाठी एकच खरेदीदार असतो?

A monopsony is a market with only one buyer and many sellers, for example a single large employer in a town buying labour. A monopoly has one seller, a duopoly two sellers, and an oligopoly a few sellers.