Although DDT, a pesticide, has been banned in the United States, it is used extensively in many other nations, primarily to curb malaria caused by mosquito bites. In some parts of the world, malaria is a serious health threat that causes severe symptoms and can cause death. Despite the problems created by extensive use of DDT, many countries find this the least expensive method for attacking malaria and mosquitoes. Using cost-benefit analysis, explain why you would favor or disapprove of the continued use of DDT in some countries.