Q: You are presented with the quiz "what are arthropods the largest phylum of?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "arthropods are the largest phylum of invertebrates" and "invertebrates are animals without a backbone". So, what's the best answer to the question?

Options are:
i. humans;
ii. absorb light energy;
iii. converting mass to energy;
iv. fish;
v. animals without a backbone;
vi. remains of prehistoric life;
vii. h2o;
viii. Earth orbiting the Sun;
The answer is:
v.