The media specialist smiled when he saw the eager students flocking to the area with the latest bestsellers. Which BEST identifies and explains the function of the word flocking as it is used in this sentence? A) It is called a gerund and it functions as a noun in this sentence. B) It is called a participle and it functions as a noun in this sentence. C) It is called an infinitive and it functions as a verb in this sentence. D) It is called a participle and it functions as an adjective in this sentence.