Name the gas which is most important for human life.

Options

A. Chlorine
B. Oxygen
C. Sulphur
D. Nitrogen

Explanation

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks for the gas that is most important for human life.

2. **Consider the Functions of Gases**: Think about the gases present in the atmosphere and their roles in human life. The primary gases include nitrogen, oxygen, carbon dioxide, and others.

3. **Focus on Respiration**: Recall that humans need a specific gas for the process of respiration, which is essential for survival.

4. **Identify the Key Gas**: The gas that is crucial for respiration is oxygen. It is used by the cells in the body to produce energy.

5. **Conclude the Answer**: Based on the information gathered, the gas that is most important for human life is oxygen.

**Final Answer**: Oxygen

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