A student is revising Animal Diversity-I: a transparent planktonic predator called an arrow worm seizes prey with curved head spines. What should the student write in the answer sheet?

Chaetognaths, or arrow worms, are marine predators with grasping spines near the head. They are important planktonic animals in marine food webs. This MCQ belongs to the Chaetognatha topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.