Concept:The poverty line in India is primarily calculated using calorie consumption as the basic measure.Explanation:The poverty line is based on the daily calorie intake of food that a person can afford.For urban areas, a person is considered above the poverty line if they can afford 2100 calories per day.For rural areas, the required calorie intake is 2400 calories per day.These calorie norms help estimate the minimum income needed for basic food consumption.The poverty line is revised periodically by the government to reflect changing costs.Answer:Option C: Calorie consumption.