6

Set 3: Boundaries

Explanation

Answer: C

PASSAGE

The mountain trail _______ challenging, offers spectacular views of the valley.

Which choice completes the text so that it conforms to the conventions of Standard English?

A. : although
B. although
C. , although✓ Correct
D. ; although

Detailed Answer Explanation

This question tests your understanding of sentence boundaries and punctuation. 'Although challenging' is an interrupter set off by commas. The sentence already has a closing comma after 'challenging.' To determine the correct answer, examine where complete thoughts begin and end. Look for independent clauses that need proper separation. A period, semicolon, or appropriate conjunction can correctly join or separate these ideas. When analyzing sentence boundaries, pay attention to how ideas flow from one sentence to the next. Correct punctuation ensures clarity and prevents confusion for readers. Review the options carefully to identify which choice creates proper sentence structure.

Key Evidence:

• "interrupter phrase"

• "comma before to match comma after"

Why others are wrong: A (Colon is grammatically incorrect here.), B (Missing opening comma for the interrupter phrase.), D (Semicolon creates a fragment.).