Correct Option: C

Given the seasonal and erratic nature of rainfall throughout the year, South India is known to know to use tank irrigation as time-tested technology for storing rainfall and runoff for a number of uses: crop irrigation, groundwater recharge, domestic use, cattle watering, etc. Tank irrigation currently accounts for more than 30 percent of all irrigated cropland in the state of Tamil Nadu and Karnataka. There exist approximately 39,000 irrigation tanks of various sizes in Tamil Nadu alone.