Select the statement which best explains commensalism:-

Options

A. One organism is benefited
B. Both the organisms are benefited
C. One organism is benefitted, other is not affected
D. One organism is benefitted, other is affected.

Answer

**Step-by-Step Solution:**

1. **Understanding Commensalism**: Commensalism is a type of symbiotic relationship between two organisms where one organism benefits while the other is neither helped nor harmed.

2. **Analyzing the Options**:
- **Option A**: "One organism is benefited." - This is partially correct but does not specify the status of the other organism.
- **Option B**: "Both the organisms are benefited." - This describes mutualism, not commensalism.
- **Option C**: "One organism is benefited, other is not affected." - This correctly describes commensalism.
- **Option D**: "One organism is benefited, other is affected." - This does not describe commensalism and suggests harm or benefit to both.

3. **Example of Commensalism**: The relationship between sucker fish and whales illustrates commensalism. The sucker fish benefits by gaining safety and transportation by attaching to the whale, while the whale remains unaffected.

4. **Conclusion**: Based on the definition and the example provided, the best explanation of commensalism is found in **Option C**: "One organism is benefited, other is not affected."

**Final Answer**: Option C - One organism is benefited, other is not affected.

---