Question 27·Hard·Boundaries
The lunar maria, vast basaltic plains that formed billions of years ago, exhibit significantly fewer craters than the surrounding highlands. In a recent conference presentation, planetary _____ argued that the maria’s smoother surfaces result from prolonged volcanic resurfacing rather than differential impact rates.
Which choice completes the text so that it conforms to the conventions of Standard English?
For SAT punctuation and "boundaries" questions, first locate the main verb and identify the full subject. Then, check each option for common errors: commas between a subject and its verb, commas splitting a title from a name, or single commas that don’t properly set off nonessential information. Quickly compare each version in your head by reading the full sentence; the correct choice will read smoothly and follow standard rules like no unnecessary commas and no broken subject–verb connection.
Hints
Locate the subject and verb
Find the main verb in the sentence (the action) and then identify all the words before it that tell you who is doing that action.
Check for commas between subject parts and the verb
Ask yourself: Should there be any commas between the person’s job title, their name, and the verb "argued"? Remember that we usually do not separate a subject from its verb with a comma.
Recall how to punctuate titles before names
Think of phrases like "scientist Marie Curie" or "composer Ludwig van Beethoven." Do these take commas between the title and the name?
Step-by-step Explanation
Identify the core sentence structure
First, strip the sentence to its main parts:
"In a recent conference presentation, planetary _____ argued that the maria’s smoother surfaces result from prolonged volcanic resurfacing rather than differential impact rates."
The main verb is "argued", so everything in the blank is part of the subject (who argued). The full subject should be a specific person with a job title: planetary ___ argued.
Understand how titles before names are punctuated
When a job title comes directly before a name and is part of identifying that person (for example, astronaut Neil Armstrong, professor Maya Patel), we do not use a comma between the title and the name.
Also, we do not place a comma between the complete subject and its verb (we do not write "Dr. Wu, argued" unless something extra is inserted after the subject).
Apply comma rules to the answer choices
Now think about what each type of comma placement would do:
- A comma between the job title and the name would break up a unit that should stay together (like writing "astronaut, Neil Armstrong").
- A comma after the name (with nothing extra following) would incorrectly separate the subject from the verb ("Dr. Wu, argued").
- Commas around the name would treat it as extra, nonessential information, which is not appropriate when the name is being used to clearly identify which planetary geologist is meant.
Only the choice that keeps the job title and name together without inserting unnecessary commas and does not put a comma between the subject and "argued" follows these rules.
State the correct completion
The subject should be written as a single, uninterrupted unit: "planetary geologist Dr. Celeste Wu argued".
So the correct answer is C) geologist Dr. Celeste Wu.