Assertion (A) : `K_(p)` is always greater than `K_(c)`.
Reason (R) : The effect of pressure is greater on the rate of reaction than the effect of concentration.

Options

A. If both (A) and (R) are correct, and (R) is the correct explanation for (A)
B. If both (A) and (R) are correct, but (R) is not the correct explanation of (A)
C. If (A) is correct, but (R) is incorrect
D. If both (A) and (R) are incorrect.

Explanation

To solve the question regarding the assertion and reason provided, we can break down the solution into clear steps.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that \( K_p \) is always greater than \( K_c \).
- This is a claim that needs to be evaluated based on the relationship between \( K_p \) and \( K_c \).

2. **Understanding the Relationship**:
- The relationship between \( K_p \) and \( K_c \) is given by the equation:
\[ K_p = K_c (RT)^{\Delta n} \]
- Here, \( R \) is the universal gas constant, \( T \) is the temperature in Kelvin, and \( \Delta n \) is the change in the number of moles of gas (moles of products - moles of reactants).

3. **Analyzing \( \Delta n \)**:
- The value of \( \Delta n \) can be positive, negative, or zero:
- If \( \Delta n > 0 \): This means there are more moles of gas in the products than in the reactants, leading to \( K_p > K_c \).
- If \( \Delta n < 0 \): This means there are fewer moles of gas in the products than in the reactants, leading to \( K_p < K_c \).
- If \( \Delta n = 0 \): This means the number of moles of gas is the same on both sides, leading to \( K_p = K_c \).

4. **Conclusion on Assertion (A)**:
- Since \( K_p \) can be greater than, less than, or equal to \( K_c \) depending on the value of \( \Delta n \), the assertion that \( K_p \) is always greater than \( K_c \) is **false**.

5. **Understanding the Reason (R)**:
- The reason states that the effect of pressure is greater on the rate of reaction than the effect of concentration.
- This statement is not universally true. The effect of pressure on the rate of reaction depends on the reaction mechanism and the specific conditions of the reaction.

6. **Conclusion on Reason (R)**:
- Since the effect of pressure does not always have a greater impact than concentration on the rate of reaction, the reason is also **false**.

7. **Final Conclusion**:
- Both the assertion (A) and the reason (R) are false. Therefore, the correct answer to the question is that both statements are incorrect.

### Final Answer:
- The assertion (A) is false, and the reason (R) is also false. Therefore, the correct option is **D**: Both assertion and reason are incorrect.