Assertion: Use of fertilisers greatly enhances crop productivity.
Reason: Irrigation is very important in increasing crop productivity.

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 and the Reason is not the correct explanation of the Assertion.
C. If Assertion is true but the Reason is false.
D. If both Assertion and Reason are false.

Answer

### Step-by-Step Solution

1. **Understanding the Assertion**: The assertion states that "Use of fertilizers greatly enhances crop productivity." Fertilizers are substances that provide essential nutrients to plants, which are crucial for their growth and development. By supplying nutrients such as nitrogen, phosphorus, and potassium, fertilizers can significantly increase the yield of crops.

2. **Understanding the Reason**: The reason states that "Irrigation is very important in increasing crop productivity." Irrigation refers to the artificial application of water to the soil to assist in the growing of crops. Water is vital for plant metabolism, including photosynthesis and nutrient absorption. Without adequate water supply, plants cannot perform their metabolic functions effectively.

3. **Evaluating the Truth of the Statements**:
- Both the assertion and the reason are true. Fertilizers do enhance crop productivity by providing necessary nutrients, and irrigation is essential for ensuring that plants have enough water to thrive.

4. **Analyzing the Connection**: While both statements are true, they do not explain each other. The assertion about fertilizers enhancing productivity does not depend on the reason about irrigation. They are both important for crop productivity, but one does not explain the other.

5. **Conclusion**: Since both the assertion and the reason are true but the reason does not serve as a correct explanation for the assertion, the correct answer is that both the assertion and reason are true, but the reason is not the correct explanation for the assertion.

### Final Answer
**Option B**: Both assertion and reason are true, but the reason is not the correct explanation for the assertion.

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