Introduction:
Living things require certain essentials to survive and thrive. These essentials include food, air, and water. In this question, the correct answer is option 'C', which states that living things need air to live.

Explanation:
1. Food:
- Food is one of the basic requirements for living things.
- It provides the necessary nutrients and energy for growth, maintenance, and repair of cells.
- Different living organisms have different dietary needs - some are herbivores, some are carnivores, and some are omnivores.

2. Water:
- Water is crucial for all living things.
- It is involved in various metabolic processes, such as digestion, circulation, and excretion.
- It helps maintain body temperature and keeps cells hydrated.
- Without water, living organisms would not be able to survive for long.

3. Air:
- The correct answer to the question is option 'C' - living things need air to live.
- Air contains oxygen, which is necessary for the process of respiration.
- Respiration is the process by which living organisms convert oxygen into energy.
- Through respiration, living things take in oxygen and release carbon dioxide.
- Different organisms have different ways of obtaining air - humans breathe through their lungs, while fish extract oxygen from water through their gills.

4. Non-living:
- Option 'B', which states non-living, is incorrect.
- Non-living things do not require food, air, or water to live because they do not possess cells or carry out metabolic processes.

Conclusion:
Living things need food, air, and water to live. While food provides nutrients and energy, water keeps cells hydrated and aids in various metabolic processes. However, air, particularly oxygen, is essential for the process of respiration. Without air, living organisms would not be able to survive. Therefore, option 'C' - air, is the correct answer.

Living things need food air and water to live