Which of the Following Constitutes a Viable Market Segment

Which of the following constitutes a viable market segment?

A) A particular group of consumers who have varying needs and wants from the offerings of the firm
B) A particular group of consumers of a single item who can be served profitably by a firm
C) A group of products and services that can be mass marketed profitably by a firm
D) A large geographic area where consumer of all the different social classes live and shop