Final answer:
Sentence 3: The dog barked loudly. The cat meowed softly. The bird chirped happily. The sun was shining. The wind blew gently. The flowers bloomed beautifully.
Step-by-step explanation:
The group of sentences that best uses a variety of sentence structures to enhance the flow and writing style of a story is Sentence 3: The dog barked loudly. The cat meowed softly. The bird chirped happily. The sun was shining. The wind blew gently. The flowers bloomed beautifully.
By incorporating different sentence structures, such as simple sentences (The dog barked loudly.), compound sentences (The sun was shining and the wind blew gently.), and complex sentences (The flowers bloomed beautifully as the wind blew gently.), Sentence 3 creates a more engaging and dynamic narrative.