John is an automotive enthusiast. He was visiting the auto show in his city. Two cars caught his attention, car A and car B. Car A was newer and it had catalytic converter. On the contrary, car B was older and didn't have catalytic converter. But he found the design of older car more attractive. Given the paragraph above, please answer correctly the following question: Which car would emit less unburned hydrocarbons, car A or car B?
car A