Photosynthesis process was first discovered by

Options

A. Priestley
B. Ingen Housz
C. Engleman
D. Blackman

Answer

### Step-by-Step Solution:

1. **Understanding Photosynthesis**:
- Photosynthesis is the process by which plants and certain organisms convert light energy, usually from the sun, into chemical energy in the form of glucose. This process requires raw materials such as water, carbon dioxide, and chlorophyll.

2. **Identifying Key Figures in Photosynthesis Research**:
- Several scientists contributed to the understanding of photosynthesis:
- **Joseph Priestley**: Known for discovering oxygen but not for discovering photosynthesis itself.
- **Engelmann**: Conducted experiments related to photosynthesis, particularly in unicellular plants, but did not discover the process.
- **Blackman**: Formulated the law of limiting factors in plant physiology, which relates to photosynthesis but is not a discovery of the process itself.
- **Jan Ingenhousz**: Recognized as the first person to discover the process of photosynthesis.

3. **Conclusion**:
- The first discovery of the process of photosynthesis is attributed to **Jan Ingenhousz**. He demonstrated that light is essential for photosynthesis and that plants produce oxygen in the presence of light.

### Final Answer:
The process of photosynthesis was first discovered by **Jan Ingenhousz**.

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