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Answer:
D. Instead of resting her sprained ankle, Justine tried to play basketball and made the injury worse.
Step-by-step explanation:
The comma effectively separates the dependent clause (a group of words that does not express a complete thought: Instead of resting her sprained ankle, from the independent clauses (complete thought): Justine tried to play basketball and made the injury worse.
The comma separates the incomplete thought from the complete one, forming a sentence.