Which of the following scientists reported that `O_2` comes from water during Photosynthesis by using potassium ferricyanide

Options

A. Van Neil
B. Ruben
C. Hill
D. Ruben and Kamen

Answer

To answer the question regarding which scientist reported that O2 comes from water during photosynthesis using potassium ferricyanide, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the scientist who demonstrated that oxygen produced during photosynthesis originates from water, specifically through the use of potassium ferricyanide.

2. **Identifying Key Terms**:
- **Photosynthesis**: The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll.
- **Potassium Ferricyanide**: A chemical compound used as a hydrogen acceptor in photosynthesis experiments.
- **Oxygen Source**: The question specifically mentions that the oxygen produced comes from water.

3. **Reviewing Historical Experiments**:
- Several scientists have contributed to our understanding of photosynthesis. Notably, Robin Hill conducted significant experiments in this area.
- Hill's experiments involved isolating chloroplasts and using potassium ferricyanide to demonstrate the release of oxygen when chloroplasts were exposed to light.

4. **Analyzing the Options**:
- **Van Niel**: Known for his work on photosynthesis but did not specifically use potassium ferricyanide.
- **Ruben**: Conducted experiments related to photosynthesis but not specifically with potassium ferricyanide.
- **Hill**: In 1937, he isolated chloroplasts and used potassium ferricyanide to show that oxygen evolved from water during photosynthesis.
- **Kamen**: Also contributed to the understanding of photosynthesis but not specifically in this context.

5. **Conclusion**: Based on the historical context and the specific use of potassium ferricyanide in the experiment, the correct answer is **Robin Hill**.

### Final Answer:
**Robin Hill**

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