Which of the following statements about fragmented industries is true?

a$.$ They are usually dominated by one or two large companies that enjoy the power to influence industry prices.

b$.$ They require companies to use focus strategies to meet specialized customer needs.

c$.$ They do not attract new entrants as they have extremely high entry barriers due to economies of scale.

d$.$ They are usually characterized by large, mass$-$production operations.

e$.$ They essentially enjoy a national brand loyalty.