While researching a topic, a student has taken the following notes:
- Environmental scientists Lisa Tiemann and Sheryl Halpern investigated soil microbial communities in urban gardens located in three different US cities.
- The scientists compared soil from raised beds in community gardens with soil from adjacent city parks.
- Raised-bed soils showed higher microbial diversity and greater nitrogen cycling activity than nearby park soils.
- In gardens older than five years, microbial diversity was especially high, regardless of city.
- The scientists conclude that raised-bed gardening practices enrich soil health over time.
The student wants to summarize the study’s results for a report. Which choice most effectively uses relevant information from the notes to accomplish this goal?
For rhetorical synthesis questions, separate broad findings from findings with narrower qualifiers. Then compare the choices for subtle changes in scope, especially options that extend a condition such as location, age, or population to a result that the notes do not connect with that condition.
Hints
Separate the findings
Distinguish the overall comparison between raised-bed and park soils from the additional finding about older gardens.
Track the age qualifier
Determine exactly which measured outcome the phrase “older than five years” modifies in the notes.
Avoid unsupported extensions
Do not choose an option that applies an age-related pattern to a measurement that the notes do not connect with garden age.
Step-by-step Explanation
Identify the overall comparison
The scientists compared raised-bed community garden soils with soils from adjacent city parks. Raised-bed soils showed greater microbial diversity and nitrogen cycling activity.
Track the scope of the age detail
The finding about gardens older than five years applies specifically to microbial diversity. The notes do not say that nitrogen cycling was especially high only in older gardens or that both measures steadily increased with age.
Compare the choices precisely
Choices A, B, and C all extend the age-related detail to nitrogen cycling in ways the notes do not support. Choice D preserves the distinction between the overall comparison and the narrower age-related diversity finding.
Select the accurate synthesis
Choice D accurately combines the overall soil comparison with the properly limited age-related result.