Answer: Economies of scope
Step-by-step explanation:
Economies of scope refers to the
proportionate saving that's gained when a company produces two or more goods, such that the cost of producing the goods is less than the cost incurred when each good is separately produced.
In such case, the average total cost of production will reduce as a result of the rise in the number of different goods that are produced.
Therefore, the concept that Microsoft use to argue that this breakup would increase total costs is Economies of scope