Correct answer: C. Long working hours and low wages
Explanation: Russian factory workers generally experienced harsh industrial conditions. Many worked for long hours and received low wages, while workplaces could be unhealthy or unsafe. Employment was often insecure, and workers had limited power in relation to factory owners and the state. These conditions created anger and encouraged workers to organise, protest, and support demands for better wages, shorter hours, and political change. The question asks about a general problem, so the central contrast is between difficult labour and inadequate payment.
Option C is correct because long working hours and low wages were major problems faced by Russian factory workers. Option A gives the opposite situation, while B is a political privilege rather than a normal labour condition. Option D is also wrong because workers did not own all factories; ownership and control remained concentrated elsewhere. A strong answer may mention hours, wages, safety, and insecurity together, but the two features in option C directly answer the question.