In commensalism,

Options

A. both partners are benefited
B. both partners are harmid
C. weaker is benefited while stronger in unharmed
D. weaker is harmed while stronger is benefited

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**: The question provides four options regarding the nature of the interaction in commensalism:
- Option 1: Both partners benefit.
- Option 2: Both partners are harmed.
- Option 3: The weaker partner benefits and the strong partner is not harmed.
- Option 4: The weak one is harmed and the strong one benefits.

3. **Evaluating Each Option**:
- **Option 1** is incorrect because, in commensalism, only one partner benefits.
- **Option 2** is also incorrect since both partners are not harmed in commensalism.
- **Option 3** correctly describes the relationship where one partner (the weaker one) benefits while the other (the stronger one) is not affected.
- **Option 4** is incorrect because it suggests that one partner is harmed, which does not occur in commensalism.

4. **Conclusion**: Based on the analysis, the correct answer is Option 3: "The weaker partner benefits and the strong partner is not harmed."