Correct answer: B. Difficult working conditions of workers
Explanation: The Industrial Revolution created factories, machines, and large groups of wage workers. Although industrialisation increased production, many workers faced long hours, low wages, unsafe workplaces, irregular employment, and crowded living conditions. These experiences made the unequal relationship between owners and workers more visible. The problem was not simply that machines existed; it was how industrial production affected people who depended on wages.
Option B is correct because difficult working conditions became a major social question and helped encourage criticism of industrial capitalism. Option A concerns royal worship, not the central effect identified here. Options C and D are unrelated distractions: noble dancing does not explain industrial social change, and sea voyages are not the main problem revealed by factory development. This issue later became important in socialist debates about labour, ownership, and equality.