A perfectly semi-permeable membrane when used to separate a solution from its solvent permits through it the passage of

Options

A. Solute only
B. Solvent only
C. Both (a) and (b)
D. None

Explanation

To solve the question regarding the behavior of a perfectly semi-permeable membrane when separating a solution from its solvent, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Semi-Permeable Membrane**:
- A semi-permeable membrane is a barrier that allows certain molecules or ions to pass through while blocking others. In this case, it separates a solution from its solvent.

2. **Identifying Components**:
- In the context of the question, we have two components: the solute (the substance dissolved in the solvent) and the solvent (the liquid in which the solute is dissolved).

3. **Direction of Movement**:
- A perfectly semi-permeable membrane allows the movement of solvent molecules. This occurs from an area of lower solute concentration (dilute solution) to an area of higher solute concentration (concentrated solution). This process is driven by the principle of osmosis.

4. **Conclusion**:
- Since the question asks what the membrane permits through it, we conclude that it permits the passage of the solvent only, not the solute.

5. **Final Answer**:
- Therefore, the correct answer to the question is option B: solvent only.