In which of the following situations is it appropriate for a firm to become a mass marketer?

A. When heavy users make up such a large proportion of the sales volume that they are the only relevant target
B. When the market is large and consists of several segments that are almost equal in size
C. When the largest segment is composed of light users, and hence, targeting them would yield the highest profits for the firm
D. When the brand is not dominant in the market, and targeting a large segment would benefit sales and profits