The 'shahnahr' repaired during the reign of  Shah Jahan in the seventeenth century was in which Indian state?

Punjab

The correct answer is Option 3 - Punjab

The Shahnahr in Punjab was repaired during Shah Jahan’s reign.

The abundance of land, available labour and the mobility of peasants were three factors that accounted for the constant expansion of agriculture in the 16th and 17th centuries. Since the primary purpose of agriculture is to feed people, basic staples such as rice, wheat or millets were the most frequently cultivated crops. Areas which received 40 inches or more of rainfall a year were generally rice-producing zones, followed by wheat and millets, corresponding to a descending scale of precipitation. Monsoons remained the backbone of Indian agriculture, as they are even today. But there were crops which required additional water. Artificial systems of irrigation had to be devised for this. Irrigation projects received state support as well. For example, in northern India the state undertook digging of new canals (nahr, nala) and also repaired old ones like the shahnahr in the Punjab during Shah Jahan’s reign.