Answer: Middle class
Explanation: In the late 1800's, which is the period of the Second Industrial Revolution or the so-called Technological Revolution, which lasted until the beginning of the WWI, that is, about 1914, when many technological innovations contributed to faster transport of goods, faster telecommunications, using artificial lighting and improving working conditions. These are innovations in the form of telegraph improvement, the development of railroads and rail transport networks, the emergence of the use of electrical energy for lighting and the possibility of working at night, etc. All this contributed to better working conditions, better management, the ability to organize workers into trade unions, reduce working hours, and better pay especially for skilled workers. Over time skilled workers began to live better with higher wages and in better environments with better living conditions that led to the emergence of a middle class.
