Concept:Intensive farming is used to get the highest possible output from limited land, so it suits areas with strong demand for food.Explanation:Urban centres have a high concentration of people.A large human population creates high demand for food and other farm produce.In response, farmers apply intensive farming methods such as heavy use of inputs and multiple cropping on small plots.Thus, intensive farming is practised in urban centres because the population is high and needs to be fed.Answer:B. human population is high