Find the odd word out

1. Selling cost: Free gifts, Advertisement hoardings, Window displays, Patents.
ANS: – Patents.

2. Market structure on the basis of competition: Monopoly, Oligopoly, Very Short Period market, Perfect competition.
ANS: – Very Short Period market

3.Features of monopoly: Price maker, Entrybarriers, Many sellers, Lack of substitutes.
ANS: – Many sellers

4. Legal monopoly: Patent, OPEC, Copyright, Trademark.