Which of the following is the evidence to show that `O_(2)` released in photosynthesis comes from water

Options

A. Isotopic oxygen `(O^(18))` supplied as `H_(2)O` appears in the `O_(2)` released
in photosynthesis.
B. Activated chloroplast in water released `O_(2)` if supplied potassium ferrocynaide or some other reducing agent in the absence of `CO_(2)`
C. Photosynthetic bacteria use `H_(2)S` and `CO_(2)` to make carbohydrates , `H_(2)O`and sulphur.
D. All of the above

Answer

To determine the evidence that shows the oxygen released in photosynthesis comes from water, we can analyze the options provided based on scientific experiments and findings.

### Step-by-Step Solution:

1. **Understanding Photosynthesis**: Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy, producing oxygen as a byproduct. The general equation for photosynthesis is:
\[ 6CO_2 + 6H_2O \xrightarrow{light \, energy} C_6H_{12}O_6 + 6O_2 \]
This indicates that water (H2O) is one of the reactants.

2. **Isotopic Evidence**: The first option states that isotopic oxygen supplied as water appeared in the oxygen released in photosynthesis. This was demonstrated by the experiments conducted by **Rubin and Kamen in 1941**. They used the isotope O-18 and found that when water containing this isotope was used, the oxygen released during photosynthesis also contained the O-18 isotope. This strongly supports the idea that the oxygen released comes from water.

3. **Chloroplast Experiments**: The second statement mentions that activated chloroplasts in water released oxygen when supplied with potassium ferrocyanide or other reducing agents, even in the absence of carbon dioxide. This experiment was conducted by **Robin Hill**, who showed that isolated chloroplasts could release oxygen without the need for carbon dioxide, indicating that the oxygen produced was indeed from water.

4. **Photosynthetic Bacteria**: The third statement refers to photosynthetic bacteria that use H2S (hydrogen sulfide) and CO2 to produce carbohydrates, water, and sulfur. This was demonstrated by **C.B. Van Neel in 1930**. While this shows a different pathway of photosynthesis, it does not directly provide evidence that oxygen from higher plants comes from water.

5. **Conclusion**: All three statements provide valid evidence regarding the source of oxygen in photosynthesis. The first two statements specifically support the idea that oxygen released during photosynthesis comes from water, while the third statement illustrates an alternative photosynthetic process.

### Final Answer:
The correct answer is **all of the above**.