Final answer:
The sentence that uses hyphens correctly is option D: Jane was the friend-–the only friend-–who offered to help Leah.
Step-by-step explanation:
The sentence that uses hyphens correctly is option D: Jane was the friend-–the only friend-–who offered to help Leah. Hyphens are used in this sentence to set off nonessential information or appositives. In this case, the phrase “the only friend” is added as extra information about “the friend” and is set off by hyphens.
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