What is something cells cannot survive without?\nOptions:\n- (A) gas\n- (B) Air\n- (C) O2\n- (D) CO2\n- (E) Ca\n- (F) O3\n- (G) Fe\n- (H) He
Hmmm, let me think. I don't want to be wrong, so I got to be careful.
User
Cells cannot survive without oxygen. And oxygen, O2, is the molecule to do it. Cells cannot survive without O2. The answer: (C).
Assistant