Oceans occupy A percent of the earth surface and have a productivity of B percent of the productivity of the whole biosphere
Choose the option which fits best for A & B in order

Options

A. 50, 50
B. 70, 10
C. 70, 30
D. 30, 70

Answer

To solve the question regarding the percentage of the Earth's surface occupied by oceans (A) and the productivity of oceans in relation to the whole biosphere (B), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for two percentages:
- A: The percentage of the Earth's surface that is covered by oceans.
- B: The percentage of the total biosphere's productivity that comes from the oceans.

2. **Determining A**:
- It is widely known that oceans cover approximately 70% of the Earth's surface. This is a well-established fact in geography and environmental science.
- Therefore, we can conclude that A = 70%.

3. **Determining B**:
- The productivity of the oceans is significantly lower than that of the entire biosphere. It is estimated that oceans contribute about 30% of the total productivity of the biosphere.
- This means that B = 30%.

4. **Final Answer**:
- Based on the above deductions, the best fit for A and B is:
- A = 70%
- B = 30%

### Conclusion:
The correct answer for the percentages is A = 70% and B = 30%.