A modifier question tests whether a describing phrase points to the right person or thing. If the phrase follows a joining word, ask who or what it describes by tracing it back to the earlier words. The phrase must describe the main noun or pronoun right after its comma. Then check for a subject and main verb, since a full sentence needs both. The right person’s name elsewhere can't fix a phrase attached to the wrong subject.
Hints
- Hint 1
Look at the describing phrase after the joining word. What does doing so send you back to in the earlier part of the sentence?
- Hint 2
Who used isotope dating to pinpoint the flooding periods? Trace in doing so to that person's work.
- Hint 3
Check how the words after and finish the sentence. A new full clause needs a subject and a main verb.
Step-by-step
Trace the phrase to its subject
Step 1Find the describing phrase
The words and in doing so, start another part of the sentence. What does that describing phrase point back to? It points to the earlier work, so we need whoever carried it out. The phrase describes the next subject, the main noun or pronoun right after its comma.
- Step 2
Name who did the work
Who carried out that work? The text says geologist Priya Ramanathan used isotope dating to pinpoint periods of intense flooding. Ramanathan used the method; the flooding periods were what she dated. The phrase refers to Ramanathan’s use of isotope dating, so the next subject must name her or stand for her.
- Step 3
Test the possible subjects
Does each opening name Ramanathan as the subject? Other researchers were enabled puts the researchers right after the comma, so in doing so would describe them as the people doing the dating. Ramanathan did the dating; the researchers received help. It enabled uses a pronoun, but it can't stand for Ramanathan, a person.
- Step 4
Finish with a subject and main verb
The opening enabling other researchers has no subject or main verb, the verb saying what a subject does or is. An -ing form can't be a main verb on its own, and it can't pair with used isotope dating as another main verb because the forms don't match. In she enabled, the subject she stands for Ramanathan and enabled is the main verb. The rest tells what her work helped the researchers confirm about flooding and climatic shifts. Choice D.