Which of the Following Is Consistent with Economies of Scope

Multiple Choice

Which of the following is consistent with economies of scope? The subscript "b" refers to a banking firm, "s" for a securities firm, "AC" is average costs and "TC" is total costs.

A) AC_{b + s} > AC_b + AC_s.
B) AC_{b + s} = AC_b + AC_s.
C) AC_{b + s} < AC_b + AC_s.
D) TC_{b + s} < TC_b + TC_s.
E) TC_{b + s} > TC_b + TC_s.