Final answer:
Oxygen is ranked first for its critical role in cellular respiration, water second due to its diverse functions in the body, and food third because humans can survive longest without it while it provides energy and nutrients necessary for bodily functions.
Step-by-step explanation:
The question asks us to rank the resources of oxygen, water, and food in terms of their importance to human survival. Considering their biological significance, the ranking from most to least critical is:
- Oxygen
- Water
- Food
Humans can only survive a few minutes without oxygen as it is essential for the cellular respiration process that produces energy. Next in importance is water; we can survive only a few days without it due to its numerous roles in the body, including maintaining cell turgidity, regulating temperature, and transporting nutrients. Food is ranked last, as humans can survive up to a month without it, though it supplies the necessary nutrients and energy required for all bodily functions.