Final answer:
Construction is the activity in the secondary sector of India's economy that employs the most labor. This sector includes industries that process raw materials into finished goods. The demand for construction work increases as the country develops and urbanizes, requiring more labor in this area.
Step-by-step explanation:
In India, the activity within the secondary sector that absorbs the most labor force is construction. The secondary sector is focused on manufacturing and processing raw materials into finished goods and includes various industries such as construction, manufacturing, and utilities. Construction, specifically, is a labor-intensive industry and requires a large workforce to create infrastructure such as buildings, roads, and bridges.
Economist Sir W. Arthur Lewis's theory on the transition of labor from primary to secondary sectors highlights that workers have greater productivity, or marginal product, within the manufacturing segment than in agriculture. This reflects why labor moves towards industries like construction within the secondary sector. In India, this transition has been evident as the country continues to develop and urbanize, requiring extensive construction work.