​In the long-run,all costs are

A) ​Fixed costs
B) Variable costs
C) Sunk Costs
D) ​Marginal Costs

As the number of facilities in a supply chain increases

A) the inventory and resulting inventory costs also increase.
B) the inventory and resulting inventory costs decrease.
C) the inventory increases and resulting inventory costs decrease.
D) the inventory decreases and resulting inventory costs increase.