Answer: 11000 units
Explanation:
Firm achieves the economies of scale when the particular quantity produced yields cost benefit to the firm. Here in the above case producing units between 10000 and 12000 units gives lesser cost of production per unit. To be cost competitive the firm has to produce at minimum efficient scale. Here the median is 2000 units so be on safer side average is 1000 units which gives 11000 units in total.
If the cost of production per unit goes up on producing additional units or lesser units then it would result in diseconomies of scale.