Assertion : Weeds are unwanted plants that grow along with the main crops.
Reason : Weeds compete with the main crops for water, minerals and sunlight and therefore reduce crop yield.

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

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Weeds are unwanted plants that grow along with the main crops."
- Weeds are indeed defined as plants that grow in places where they are not wanted, particularly in agricultural fields where they can interfere with the growth of cultivated crops.

2. **Understanding the Reason**:
- The reason provided is that "Weeds compete with the main crops for water, minerals, and sunlight and therefore reduce crop yield."
- This is true because weeds absorb nutrients, water, and light that are essential for the growth of the main crops, leading to reduced crop yields.

3. **Analyzing the Relationship**:
- The assertion and reason are both true statements.
- The reason explains why weeds are considered unwanted plants: they compete with crops for vital resources, which can hinder the crops' growth and productivity.

4. **Conclusion**:
- Since both the assertion and reason are true, and the reason correctly explains the assertion, we can conclude that the correct answer is that both the assertion and the reason are true, and the reason is the correct explanation of the assertion.

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

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