Assertion : Carbocation are planar in nature.
Reason : Carbocations are `sp^(2)` hybridised.

Options

A. If both assertion and reason are correct and reason is correct explanation for assertion.
B. If both assertion and reason are correct but reason is not correct explanation for assertion.
C. If assertion is correct but reason is incorrect.
D. If both assertion and reason are incorrect.

Explanation

To solve the question regarding the assertion and reason about carbocations, we can break it down into a step-by-step analysis:

### Step 1: Understand the Assertion
The assertion states that "Carbocations are planar in nature."
- A carbocation is a positively charged carbon atom that has three bonds and one empty p-orbital.

**Hint:** Recall that the geometry of a molecule can be determined by its hybridization.

### Step 2: Analyze the Structure of a Carbocation
For example, consider the structure of a simple carbocation like CH3-CH^+-CH3 (where the carbon with the positive charge is the central carbon).
- This central carbon is bonded to three other atoms (two methyl groups and one hydrogen).

**Hint:** Count the number of bonds to the central carbon to determine its hybridization.

### Step 3: Determine the Hybridization
The central carbon in the carbocation has three sigma bonds and no lone pairs.
- The hybridization of a carbon atom with three sigma bonds is `sp^2`.

**Hint:** Remember that `sp^2` hybridization corresponds to a trigonal planar geometry.

### Step 4: Conclude the Planarity
Since the hybridization of the carbocation is `sp^2`, it adopts a trigonal planar shape.
- This means that the molecule is indeed planar.

**Hint:** Visualize the geometry of `sp^2` hybridized molecules to confirm their planarity.

### Step 5: Analyze the Reason
The reason given is "Carbocations are `sp^2` hybridized."
- This statement is true, as we have established that carbocations have `sp^2` hybridization.

**Hint:** Check if the reason logically supports the assertion.

### Step 6: Final Conclusion
Both the assertion and the reason are correct, and the reason provides a valid explanation for the assertion.
- Therefore, the correct answer is that both the assertion and reason are true, and the reason justifies the assertion.

**Final Answer:** Option A - Both assertion and reason are correct, and the reason is the correct explanation for the assertion.