PSAT Writing and Language Question 632: Answer and Explanation

Question: 632

• A. NO CHANGE
• B. found that Io, a moon of Jupiter has
• C. found that Io, a moon of Jupiter, has
• D. found that Io a moon, of Jupiter has

Correct Answer: C

Explanation:

(C) The commas correctly surround the clarification of what Io is. This grammatical construction is known as an "appositive," which is when an interchangeable name for what comes before is surrounded with commas. For example, "My oldest daughter, the Prime Minister, is well respected." The other options do not provide sufficient pauses.