If the external solution balances the osmotic pressure of the cytoplasm then it is said to be (A)_____

Answer

To solve the question, we need to understand the relationship between osmotic pressure and the types of solutions in relation to plant cells.

### Step-by-Step Solution:

1. **Understanding Osmotic Pressure**:
- Osmotic pressure is the pressure required to prevent the flow of water across a semipermeable membrane. It is a measure of the tendency of water to move into a solution due to solute concentration.

2. **Identifying the Conditions**:
- The question states that the external solution balances the osmotic pressure of the cytoplasm. This means that the concentration of solutes outside the cell is equal to the concentration of solutes inside the cell.

3. **Types of Solutions**:
- There are three types of solutions in relation to osmotic pressure:
- **Isotonic Solution**: The concentration of solutes is the same inside and outside the cell.
- **Hypotonic Solution**: The concentration of solutes is lower outside the cell than inside, leading to water entering the cell and causing it to swell.
- **Hypertonic Solution**: The concentration of solutes is higher outside the cell than inside, leading to water leaving the cell and causing it to shrink.

4. **Conclusion**:
- Since the external solution balances the osmotic pressure of the cytoplasm, it indicates that the solute concentrations are equal. Therefore, the correct term to fill in the blank is "isotonic solution".

### Final Answer:
(A) isotonic solution