Answer:
The best step for the engineer to take in order to design a car that produces less air pollution would be to conduct thorough research on the sources and causes of air pollution in the city. This research should include an analysis of the specific pollutants that are present in the city's air, as well as the ways in which these pollutants are produced by various sources such as transportation, industry, and power generation.
Once the engineer has a clear understanding of the sources and causes of air pollution in the city, they can begin to explore different technologies and design solutions that can reduce emissions from cars. This may include the use of alternative fuels, advanced emissions control systems, or hybrid or electric powertrains.
It's also important for the engineer to consider the overall efficiency of the car, not only the emissions. For example, if the car is more aerodynamic, it will use less energy to move and produce less emissions in the process.
Finally, they should test and verify the effectiveness of their design through real-world testing and validation before releasing it to the market.