You are presented with the quiz "_ lack respiratory and excretory systems." But you don't know the answer, so you turn to your teacher to ask for hints. He says that "echinoderms lack respiratory and excretory systems" and "echinoderms are represented by the starfish". So, what's the best answer to the question?

Choose your answer from: i. graptolites; ii. insects; iii. ferns; iv. barnacles; v. fossil fuels; vi. Allergies; vii. starfish; viii. parasites;
Answer:
vii.