Which of the following is an emissions tax? a) pay drivers $0.20 for each 10% reduction in automobile emissions. b) specify the type of catalytic converter to be installed on motorized vehicles to reduce automobile emissions. c) charge drivers $0.20 for each unit of automobile emissions. d) transfer the ownership of city traffic to a private firm that charges automobile drivers a profit- maximizing price to enter the city center, based in part on the pollution capacity of the atmosphere