Which of the following processes does not increase `CO_2` in air ?

Options

A. Respiration
B. Photosynthesis
C. Burning of petrol
D. Pneumatic depletion of vegetation

Explanation

To determine which process does not increase carbon dioxide (CO₂) in the air, we can analyze each option provided. Here’s a step-by-step solution:

### Step 1: Understand the Processes
We need to look at the processes mentioned in the question and understand how each one affects the levels of CO₂ in the atmosphere.

### Step 2: Analyze Respiration
- **Respiration**: This process involves the breakdown of glucose (sugar) in the presence of oxygen to produce energy (ATP), releasing CO₂ as a byproduct.
- **Conclusion**: Respiration increases CO₂ in the air.

### Step 3: Analyze Photosynthesis
- **Photosynthesis**: This process uses CO₂ and water, along with sunlight and chlorophyll, to produce glucose and oxygen.
- **Conclusion**: Photosynthesis decreases CO₂ in the air because it consumes CO₂.

### Step 4: Analyze Burning of Petrol
- **Burning of Petrol**: This combustion process releases CO₂ into the atmosphere as a pollutant.
- **Conclusion**: Burning petrol increases CO₂ in the air.

### Step 5: Analyze Depletion of Vegetation
- **Depletion of Vegetation**: Plants absorb CO₂ during photosynthesis. If vegetation is depleted, there are fewer plants to absorb CO₂, leading to an increase in CO₂ levels.
- **Conclusion**: Depletion of vegetation increases CO₂ in the air.

### Final Conclusion
After analyzing all the processes, we find that **photosynthesis** is the only process that does not increase CO₂ in the air. Therefore, the correct answer is:

**Photosynthesis (Option 2)**.

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