Amazon rainforests are considered as 'lungs of the planet' as they contribute______of the total oxygen in the earth's atmosphere.
(a) 10 %
(b) 15 %
(c) 20 %
(d) 30 %

Options

A. `10%`
B. `15%`
C. `20%`
D. `30%`

Explanation

To solve the question regarding the contribution of the Amazon rainforests to the total oxygen in the Earth's atmosphere, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Context**: The Amazon rainforest is often referred to as the "lungs of the planet." This term is used because of its significant role in producing oxygen and absorbing carbon dioxide.

2. **Identifying the Contribution**: The question asks for the percentage of total oxygen that the Amazon rainforest contributes to the Earth's atmosphere.

3. **Recalling Key Information**: It is widely recognized that the Amazon rainforest contributes approximately 20% of the total oxygen in the Earth's atmosphere. This is a well-documented fact in environmental science.

4. **Choosing the Correct Option**: Given the options provided:
- (a) 10%
- (b) 15%
- (c) 20%
- (d) 30%

The correct answer based on the information recalled is (c) 20%.

5. **Final Answer**: Therefore, the Amazon rainforests contribute **20%** of the total oxygen in the Earth's atmosphere.