Answer:
C. The firms in this industry have diseconomies of scale.
Step-by-step explanation:
Diseconomy of scale occurs when the cost with the factors of production grows more than the output resulting from the investment, resulting in an increase in the average cost per unit produced.
In the case in question, the factor of production works. Investment is the cost of the total manpower of managers and employees. If after this investment the final production decreased (-14.4% and -3.1% respectively), this means that these firms had diseconomies of scale. Because they are firms of the same nature, it is pertinent to affirm that the sector of these firms presented diseconomies of scale.