By Which Formula Can the Concept of Economies of Scope

Multiple Choice

By which formula can the concept of economies of scope be represented?

A) Average Costs (X,Y) < Average Costs (X) + Average Costs (Y)
B) Total Revenues (X,Y) < Total Revenues (X) + Total Revenues (Y)
C) Average Costs (X,Y) > Average Costs (X) + Average Costs (Y)
D) Total Revenues (X,Y) > Total Revenues (X) + Total Revenues (Y)