Which of the Following Expressions Describes Economies of Scope

Multiple Choice

Which of the following expressions describes economies of scope?

A) AC_A+B│X₁,X₂│ < AC_A│X₁,0│ + AC_B│X₂,0│
B) AC_A+B│X₁,X₂│ > AC_A│X₁,0│ + AC_B│X₂,0│
C) AC_A+B│X₁,X₁│ < AC_A│X₁,0│ + AC_B│X₁,0│
D) AC_A+B│X₁,X₂│ = AC_A│X₁,0│ + AC_B│X₂,0│