Explanation:

- The correct answer is Option 2: 78%

- The air we breathe is predominantly composed of nitrogen.

- Nitrogen makes up approximately 78% of the Earth's atmosphere by volume.

- This abundance is crucial for life, as it participates in the nitrogen cycle.

- Option 1: 82%

- This figure is higher than the actual percentage of nitrogen in the air.

- Option 3: 76%

- This figure is slightly lower than the actual percentage.

- Option 4: 74%

- This percentage is also lower than the actual nitrogen content in the air.

The correct answer is Option 2: 78%.

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