The correct answer is option 3: the manufacturers from Lancashire and Manchester.

During the nineteenth century, the implementation of factory legislation in India was influenced by various factors. The pressure on the Government of India to introduce factory legislation was mainly driven by the manufacturers from Lancashire and Manchester, who were concerned about the competition from the Indian textile industry.

These British manufacturers were influential and had significant economic interests in India. They saw the Indian textile industry as a threat to their own industry and pushed for regulations that would restrict the working conditions and productivity of Indian factories. They lobbied the British government, which had control over India at that time, to introduce factory legislation to protect their own interests.

The trade unionists and socialists in India did contribute to the push for factory legislation, but their influence was not as significant as that of the British manufacturers. The Indian National Congress, a political organization that played a crucial role in India`s independence movement, did not have a direct influence on the implementation of factory legislation in the nineteenth century.

To summarize, the implementation of factory legislation in nineteenth-century India was primarily a result of pressure from the manufacturers in Lancashire and Manchester who wanted to protect their own economic interests.