An economy of scope is BEST illustrated by being able to eliminate or reduce costs by
选项：

A: combining related value-chain activities of different businesses into a single operation.
B: performing all of the value chain activities of related sister businesses at the same location.
C: extending the firm's scope of operations over a wider geographic area.
D: expanding the size of a company's manufacturing plants.
E: having more value chain activities performed in-house rather than outsourcing them.