Why did the idea of using bus tokens to pay people from favelas for bringing in trash to a central location cost the city of Curitiba nothing? Question 17Select one: a. The cost of operating the buses is paid for with the proceeds from a tax on gasoline b. Sales of recyclables recovered from the trash are more than enough to pay for the cost of the bus tokens c. The city operates a waste-to-energy power plant, and the savings in terms of fuel costs more than makes up for the cost of the bus tokens d. The city pays the bus companies on the basis of how far the buses travel each day