The correct answer is option 3 - Cotton and Textile industry. This industry has the maximum employment of labor compared to the other industries listed.
Iron and Steel industry (option 1) is known for its heavy machinery and automation, which reduces the need for a large number of laborers. Chemicals and Fertilizer industry (option 2) also relies heavily on machinery and automation in its production processes, leading to a lower demand for labor.
On the other hand, the Cotton and Textile industry (option 3) is labor-intensive, as it involves activities such as spinning, weaving, dyeing, printing, and garment-making, that require a significant amount of manual labor. The process of transforming raw cotton into finished textile products requires a large workforce in order to meet the demand for textiles.
The Cement industry (option 4) is relatively less labor-intensive as it involves more mechanized processes, such as crushing, grinding, and heating limestone and other materials to produce cement.
Therefore, out of the given options, the Cotton and Textile industry has the maximum employment of labor.