Final answer:
The textile manufacturing industry was responsible for creating thousands of wage-earning jobs in the early nineteenth century, due to the mechanization and centralization of production in newly established textile mills. So, the correct answer is option a.
Step-by-step explanation:
The industry that created thousands of wage-earning jobs in the early part of the nineteenth century was textile manufacturing. Northern industrialization, particularly after the War of 1812, saw the expansion of industrialized manufacturing starting in the New England region.
Wealthy merchants built water-powered textile mills along rivers, initiating new modes of production that were centralized within the confines of the mill itself. Operations in these mills significantly changed the nature of work by deskilling tasks and relying on mechanized sources like water and steam power to drive machines.
Previously, production was carried out by skilled artisans who produced goods by hand. With the advent of the textile mills, wage laborers, often young women from rural areas, took on specialized, repetitive tasks. This shift from handicraft production to mechanized, centralized factory work created a demand for wage labor and contributed to the growth of the textile industry as the leading sector during the Industrial Revolution.