Photosynthesis is an important biological process for life on earth because

Options

A. It is responsible for release of `O_2`
B. It is primary source of food on earth
C. It is the only process which can utilise the solar energy
D. All of the above

Answer

### Step-by-Step Solution:

1. **Understanding Photosynthesis**:
- Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy (usually from the sun) into chemical energy in the form of glucose. This process primarily occurs in the chloroplasts of plant cells.

2. **Release of Oxygen**:
- One of the byproducts of photosynthesis is oxygen (O2). During the process, plants take in carbon dioxide (CO2) and water (H2O) and, using sunlight, convert these into glucose and oxygen. The oxygen produced is essential for the respiration of most living organisms, including humans.

3. **Primary Source of Food**:
- Photosynthesis is the foundation of the food chain. Plants, known as producers, synthesize their own food and serve as the primary source of energy for herbivores (primary consumers) and, subsequently, for carnivores (secondary consumers). Thus, it is vital for sustaining life on Earth.

4. **Utilization of Solar Energy**:
- Photosynthesis is unique because it is the only biological process that can directly convert solar energy into chemical energy. This ability to harness sunlight is crucial for life on Earth, as it powers the majority of ecosystems.

5. **Conclusion**:
- Given the importance of photosynthesis in releasing oxygen, providing food, and utilizing solar energy, we can conclude that all the statements regarding its significance are correct. Therefore, the answer to the question is "all of the above".

### Final Answer:
Photosynthesis is an important biological process for life on Earth because it is responsible for the release of O2, it is the primary source of food on Earth, and it is the only process that can utilize solar energy. Thus, the correct answer is "all of the above".

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