Which is water soluble?
(a) Phycobilin
(b) Carotene
(c) Xanthophyll
(d) Chlorophyll

Options

A. Phycobilin
B. Carotene
C. Xanthophyll
D. Chlorophyll.

Answer

To determine which pigment is water-soluble among the given options, we can analyze each pigment based on their properties.

### Step-by-Step Solution:

1. **Identify the pigments**: The pigments given in the question are:
- (a) Phycobilin
- (b) Carotene
- (c) Xanthophyll
- (d) Chlorophyll

2. **Analyze Phycobilin**:
- Phycobilin is known for its water solubility. It is a pigment found in certain algae, particularly red algae and cyanobacteria. This characteristic makes it distinct from the other pigments listed.

3. **Analyze Carotene**:
- Carotene is a pigment that is primarily fat-soluble. It has long hydrocarbon chains, which contribute to its solubility in fats rather than water.

4. **Analyze Xanthophyll**:
- Xanthophyll is another pigment that is also fat-soluble. Similar to carotene, it contains long hydrocarbon chains that prevent it from dissolving in water.

5. **Analyze Chlorophyll**:
- Chlorophyll is the pigment responsible for photosynthesis in plants and is also fat-soluble. It contains a long hydrocarbon tail, making it insoluble in water.

6. **Conclusion**:
- Among the options, only phycobilin is water-soluble. Therefore, the correct answer is (a) Phycobilin.

### Final Answer:
The water-soluble pigment among the options is (a) Phycobilin.

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