Which of the following would most likely create the setting for an oligopoly?

A、 government grants Alex, Trent, and Alyse each a patent for their respective molybdenumBased electric car batteries
B、 market demand is two or more times less than quantity needed to produce at the minimum ofThe AC curve
C、 market demand is two or more times more than quantity needed to produce at the minimum ofThe MC curve
D、 insurmountable technological difficulty associated with producing similar products acts as an Effective barrier to entry