I think it is Onomatopoeia because it is saying "A loud roar in the distance comes nearer and nearer, and everyone looks worried. "So the sentence is showing the loud roar and the people looking around because it shows the sound of the roar. Onomatopoeia is the use of descriptive words that sound or mimic the noise they are describing, so it would make sense. Let me know if im wrong, hope it helps though!
