Answer the following question: You are presented with the quiz "Cells are the basic units of the structure and function of what?"   But you don't know the answer, so you turn to your teacher to ask for hints. He says that "cells are the basic units of the structure and function of living things" and "tigers are the largest of the living cats".   So, what's the best answer to the question?

Options: 1. water; 2. mammals; 3. ice; 4. tigers; 5. animals; 6. humans; 7. plants; 8. the Sun;
Answer:
4.