The correct answer is A. Capital.
Step-by-step explanation
In production or the process of creating products three elements are required, these are land, labor and finally capital. To begin with, the land is a term used to refer to natural resources used in the production, for example, water, oil, wood, stones, iron, steel, gold, among others, that were transformed into new objects with different utilities. On the other hand, labor is a term used to refer to all workforce of people that is necessary for the production process. Although there are machines, the capital refers to all means of production of a company, for example, machines, engines, factories, among others. Those were developed across from antiquity, nevertheless, in the Industrial Revolution was the moment when all capital goods were improved to facilitate the production process. So the correct answer is A. Capital.