The correct answer to the question is option 3: rising wages and tighter labor market.
Private investment in Indian agriculture is primarily focused on labor-saving mechanization. This means that farmers are investing in machinery and equipment that can perform tasks that were previously done by manual labor.
The reason behind this shift towards mechanization is the rising wages and tighter labor market in the agricultural sector. As wages increase and the availability of labor decreases, farmers are finding it more efficient and cost-effective to invest in machines that can perform tasks more quickly and efficiently.
Rising wages and tighter labor market mean that it is becoming more expensive and difficult for farmers to find and hire labor. By investing in labor-saving mechanization, farmers can reduce their reliance on manual labor and increase their productivity.
It is important to note that the other options presented in the question are not the main drivers for private investment in labor-saving mechanization. Rising productivity may be a result of using mechanization, but it is not the main reason for the investment. Rising inequality and debt write-off by the government are not directly related to private investment in mechanization.