PSAT Writing and Language Question 305: Answer and Explanation

Question: 305

• A. NO CHANGE
• B. ice cap; and if
• C. ice cap and if
• D. ice cap; if

Correct Answer: D

Explanation:

Difficulty: Medium

Category: Sentence Structure: The Basics

Getting to the Answer: The underlined comma separates two independent clauses, each expressing a complete thought with a subject and predicate verb ("Scientists estimate" and "sea levels might rise"). Remember that semicolons combine two independent clauses, while commas can join independent clauses only when followed by a FANBOYS conjunction. Choice (D) is correct because it properly joins the independent clauses with a semicolon. The other answer choices are not valid ways to join independent clauses. (A) creates a run-on because it joins independent clauses with only a comma. (B) adds an unnecessary "and" after the semicolon. (C) omits the necessary comma before "and."