A monopoly is most likely to emerge in a market when

Answer: there is only one producer of a commodity

Explanation: In simple words, monopoly refers to a market structure in which there is only one participant in the market who is making available the commodity to the customers.

Monopoly can arise from a number of factors such as patents rights, new invention etc. Sometimes the govt. of a country finds it suitable to handle a particular industry for the national benefit such as defense.

Although monopolist is the single producer but still he or she cannot charge any price as the rule of price and demand is applies to monopoly also.