Assertion : At a point in space, the electric field points towards north. In the region, surrounding this point the rate of change of potential will be zero along the east and west.
Reason : Electric field due to a charge is the space around the charge.

Options

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

Explanation

To analyze the assertion and reason provided in the question, we will break it down into logical steps.

### Step-by-Step Solution:

1. **Understanding Electric Field Direction**:
- The assertion states that at a point in space, the electric field points towards the north. This means that if we place a positive test charge at this point, it would experience a force directed towards the north.

2. **Electric Potential and Electric Field Relationship**:
- The electric field (E) is related to the electric potential (V) by the equation:
\[ E = -\frac{dV}{dr} \]
- This indicates that the electric field points in the direction of decreasing potential. Therefore, if the electric field points north, the potential will decrease as we move towards the north.

3. **Equipotential Surfaces**:
- An equipotential surface is a surface where the electric potential is constant. Along such surfaces, the electric field does not perform work, and thus, the potential does not change.
- Since the assertion mentions that the rate of change of potential will be zero along the east and west directions, it implies that the east-west direction is an equipotential surface.

4. **Conclusion about the Assertion**:
- If the electric field points north, and the potential is constant in the east-west direction, then the assertion is correct. The potential does not change as we move east or west, confirming that the rate of change of potential is indeed zero in those directions.

5. **Analyzing the Reason**:
- The reason states that the electric field due to a charge is the space around the charge. This is a general statement about electric fields but does not directly support the assertion regarding the specific scenario of potential change along the east-west direction.

6. **Final Evaluation**:
- The assertion is true, while the reason, although true in a general sense, does not provide a relevant explanation for the assertion. Therefore, the assertion is correct, but the reason is not a valid justification for the assertion.