Final answer:
The correct order from the highest to the lowest carbon emitter for the given modes of transportation is: Commercial jet airplanes, Cruise ships, Diesel trains, Electric cars. The correct answer is option a.
Step-by-step explanation:
When placing modes of transportation in order depending on how much carbon they emit into the atmosphere, the source that releases the most should come first, followed by decreasing emitters. Considering the impact of various transportation methods on carbon dioxide emissions, the order would be: Commercial jet airplanes (because they emit a significant amount of carbon per kilometer and often cover large distances), followed by cruise ships (which are also quite energy-intensive), then diesel trains (which are more efficient per passenger or per-ton basis but still fueled by fossil fuels), and finally, electric cars (which have the potential to use renewable sources of electricity).
Therefore, the correct sequence from highest to lowest carbon emitter among the given options is: a) Commercial jet airplanes, Cruise ships, Diesel trains, Electric cars.