Question 9·Medium·Rhetorical Synthesis
While researching eco-friendly travel options, a student has taken the following notes:
- An average passenger car emits about 404 grams of CO₂ per mile.
- A fully occupied intercity train emits about 89 grams of CO₂ per passenger-mile.
- For a 500-mile trip, choosing the train instead of the car avoids roughly 157,500 grams of CO₂ emissions.
- Both cars and trains rely on fossil fuels, but trains transport many passengers at once.
The student wants to emphasize that trains produce far fewer emissions than cars on a long-distance trip. Which choice most effectively uses relevant information from the notes to accomplish this goal?
For rhetorical synthesis questions, always start by pinpointing the exact purpose stated in the question (for example, emphasize a benefit, explain a cause, or highlight a contrast). Then scan the notes to identify which specific piece of information most directly serves that purpose. Finally, test each answer choice to see which one actually uses that key information and keeps the focus and tone aligned with the goal, eliminating choices that are off-topic, too general, or that weaken the intended emphasis. This approach is faster and more reliable than just picking a statement that sounds generally true.
Hints
Focus on the exact goal
Underline the phrase in the question that states the goal: the student wants to emphasize that trains produce far fewer emissions than cars on a long-distance trip. Any choice that does not clearly show lower emissions on a trip should be suspect.
Choose the most relevant note
Look back at the bulleted notes. Which note directly connects trains, cars, and a specific long-distance trip while highlighting a big difference in emissions?
Check what each choice actually emphasizes
For each answer, ask: Does it (1) talk about emissions, (2) make a clear comparison between trains and cars, and (3) relate to a long-distance trip? Eliminate choices that are mostly about efficiency, fossil fuels in general, or that weaken the difference.
Step-by-step Explanation
Identify the writer’s goal
The prompt states that the student wants to emphasize that trains produce far fewer emissions than cars on a long-distance trip. So the best sentence must:
- Focus on emissions, not just efficiency or fossil fuels.
- Make a clear comparison between trains and cars.
- Relate specifically to a long-distance trip, not just per-mile data in the abstract.
Decide which note best supports that goal
Look at the notes and ask which one most strongly supports the idea of far fewer emissions on a long trip:
- The 404 vs. 89 grams numbers compare emissions per mile or per passenger-mile, but they don’t mention a full trip.
- The 500-mile trip note gives a big total amount of CO₂ avoided on a specific long-distance journey, directly tying trains, cars, and emissions together.
- The notes about fossil fuels and carrying many passengers explain why trains can be efficient, but they don’t directly quantify emissions or stress how much less they emit on a trip. The 500-mile-trip note is therefore the most powerful for emphasizing the emissions difference on a long-distance journey.
Match each answer choice to the goal and select the best one
Now see how each answer choice uses the notes:
- Choice A talks about fossil fuels and carrying many passengers (efficiency) but never mentions emissions or a trip length, so it does not meet the goal.
- Choice C gives the per-mile and per passenger-mile numbers, which shows trains emit less, but it doesn’t mention a long-distance trip or the total amount avoided.
- Choice D says trains emit less but immediately adds that they still contribute to climate change, which weakens the emphasis on “far fewer” emissions.
- Choice B uses the 500-mile-trip note to show how much CO₂ is kept out of the atmosphere on a specific long-distance journey, clearly emphasizing a large reduction in emissions when choosing the train.
Therefore, the correct answer is: B) Taking a 500-mile journey by train instead of by car can keep about 157,500 grams of CO₂ out of the atmosphere.