The correct option is A Average cost
The industrial revolution was the transition to new manufacturing process in the period from 1760 to sometime between 1820 and 1840. This transition includes going from hand production methods to machine, new chemical manufacturing and iron production process. This gave rise to the development of machine tools and factory system. Due to the use of machine, large number of goods could be produced in a very short period of time. Vast number of goods were produced in a smaller period of time due to which the average cost of production reduced. This increased the profitability of the products and company earned good revenue.