Assertion : Dipole - dipole forces acting between the molecules possessing permanent dipole , are weaker than ion - ion interactions .
Reason : The attractive forces decrease with the increase of distance between the dipoles .

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion .
B. If both assertion and reason are true but reason is not the correct explanation of assertion .
C. If assertion is true but reason is false .
D. If both assertion and reason are false .

Explanation

To solve the assertion and reason question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that dipole-dipole forces acting between molecules with permanent dipoles are weaker than ion-ion interactions.
- **Explanation**: Dipole-dipole forces arise from the interactions between the positive end of one polar molecule and the negative end of another. These forces are generally weaker than ion-ion interactions, which involve full charges (ions) attracting each other.

2. **Understanding the Reason**:
- The reason states that attractive forces decrease with the increase of distance between the dipoles.
- **Explanation**: This is a fundamental principle in chemistry; as the distance between charged entities increases, the force of attraction or repulsion between them decreases. This applies to both dipole-dipole interactions and ion-ion interactions.

3. **Comparing the Strengths of Interactions**:
- Ion-ion interactions are much stronger than dipole-dipole interactions because ions have full charges, while dipoles have only partial charges.
- The strength of dipole-dipole interactions is influenced by the distance between the dipoles, which supports the assertion.

4. **Conclusion**:
- Both the assertion and the reason are true. Additionally, the reason correctly explains why the assertion is true, as the decrease in attractive forces with distance applies to dipole-dipole interactions.

### Final Answer:
- **Both the assertion and reason are true, and the reason is the correct explanation of the assertion.**