Q: You are presented with the quiz "Cells cannot survive without plants breathing into what?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "cells cannot survive without oxygen" and "plants breathe oxygen into the atmosphere". So, what's the best answer to the question?

Options are:
[I] carbon dioxide;
[II] seas;
[III] Sulfur dioxide;
[IV] lungs;
[V] water vapor;
[VI] atmosphere;
[VII] water;
[VIII] water tanks;
The answer is:
[VI]