In commensalism:

Options

A. both partners are benefitted
B. both partners are harmed
C. weaker is benefitted while stronger is unharmed
D. None of the above

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. **Identifying the Organisms**:
- In a commensal relationship, we can denote the two organisms as A and B. Organism A benefits from the relationship, while organism B remains unaffected.

3. **Examples of Commensalism**:
- A classic example is the relationship between epiphytes (plants that grow on other plants) and a mango tree. The epiphytes benefit by gaining access to sunlight while the mango tree is not harmed.
- Another example is the suckerfish that attaches itself to a shark. The suckerfish gains protection and nourishment while the shark is unaffected.

4. **Analyzing the Options**:
- **Option A**: Both partners are benefited - This is incorrect as it describes mutualism, not commensalism.
- **Option B**: Both partners are harmed - This is also incorrect as it does not describe any symbiotic relationship.
- **Option C**: Weaker partner is benefited while the stronger is unharmed - This correctly describes commensalism.
- **Option D**: None of the above - This is incorrect since option C is correct.

5. **Conclusion**:
- The correct answer is **Option C**, which states that in commensalism, the weaker partner benefits while the stronger partner is unharmed.