In the given sentence above, the word "whistle" most likely symbolizes power. The correct answer would be the third option. The "whistle" serves as the symbol of power in this sentence because it was like a savior of the person who had been splashing in the shallow end. In addition, it was also like a siren. A siren is a device with a loud, prolonged sound which usually signals a warning making anyone who hears this, pays attention to it.