In private companies workers are taking early retirement as the work is exhausting and repetitive. From Marx's perspective what does this situation reflect?

Alienation

The correct answer is Option (3) - Alienation.

Marx, Max Weber and Emile Durkheim associated a number of social features with industry, such as urbanisation, the loss of face-to-face relationships that were found in rural areas where people worked on their own farms or for a landlord they knew, and their substitution by anonymous professional relationships in modern factories and workplaces. Industrialisation involves a detailed division of labour. People often do not see the end result of their work because they are producing only one small part of a product. The work is often repetitive and exhausting. Yet, even this is better than having no work at all, i.e., being unemployed. Marx called this situation alienation, when people do not enjoy work, and see it as something they have to do only in order to survive, and even that survival depends on whether the technology has room for any human labour.