Concept:A participial phrase (like "Running quickly") must clearly refer to the subject of the main clause. The subject must immediately follow the phrase to avoid a dangling modifier.Explanation:In option B, "Running quickly, he crossed the finish line", the subject "he" directly follows the participial phrase. This makes it clear that "he" is the one running. Option A has a dangling participle because "the finish line" cannot run. Option C also dangles — "the race" cannot run. Option D is illogical: "the line crossed him" reverses the action. Only option B correctly places the subject after the phrase, giving a clear and grammatical sentence.Answer:B. Running quickly, he crossed the finish line.