A modifier question tests whether you can connect an opening describing phrase to the right noun. Read through its comma, and name who or what the phrase describes. An opening phrase about doing something describes the main noun right after the comma, so that noun must name whoever or whatever did it. Read each choice's first noun group, because mentioning the right name later doesn't fix a wrong noun at the start.
Hints
- Hint 1
Start with the work described before the comma. Who would be carefully cataloging the growth rings in the samples?
- Hint 2
Find the main noun right after the comma. Read it as the one doing the cataloging, and check whether that makes sense.
Step-by-step
Name who did the cataloging
Step 1Find who the opening phrase describes
The words After carefully cataloging the seasonal growth rings in hundreds of ancient driftwood samples describe work with samples but don't name who did it. Who does the phrase describe? It describes the people doing the cataloging, so the main noun after the comma must name those people. An opening describing phrase points to that noun, which means we need to read the first noun of each choice rather than skim for a familiar name.
- Step 2
Test the noun at each start
Which noun does each start make responsible for cataloging the seasonal growth rings? The start several abrupt warming periods makes periods the main noun after the comma, so it says warming periods cataloged the samples. With the Larsen Ice Shelf, the shelf is the main noun, which gives that work to the place being studied. In it was determined, it doesn't name anyone who cataloged the samples. Naming the people later in these sentences can't repair the link, because the opening phrase describes the main noun right after its own comma.
- Step 3
Put the catalogers in the subject's place
In the research team determined, the main noun is team, which can do the work described in After carefully cataloging. The team is the subject the opening phrase needs. Does the rest form a full sentence with that subject? The verb determined tells us what the team did, and the words beginning with that tell us what it found about warming periods at the Larsen Ice Shelf. Choice D.