A : Light harvesting complexes ( LHC) on thylakoid membrane broaden the range of light absorption.
R: They transfer ` e^(-)` to reaction centre.

Options

A. If both Assertion % Reson ar true and the reason is the correct explanation of the asserition the mark (1)
B. If both Assertion % Reason are true but the reason, is not the correct explanation of the assertion ,then mark (2)
C. If Assetion is true statement but Reason is false , The mark (3)
D. If both Assertion and Reason are false statements, the mark (4)

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that light harvesting complexes (LHC) on the thylakoid membrane broaden the range of light absorption.
- LHCs, also known as photosystems, are crucial for capturing light energy during photosynthesis.

2. **Identifying Types of Photosystems**:
- There are two types of photosystems: Photosystem I (PSI) and Photosystem II (PSII).
- PSI has a reaction center that absorbs light maximally at 700 nm, while PSII absorbs light maximally at 680 nm.

3. **Role of Accessory Pigments**:
- Besides chlorophyll A, there are accessory pigments (like chlorophyll B, xanthophylls, and carotenoids) that absorb light in different wavelengths (violet, indigo, green, yellow, and orange).
- These pigments help in capturing a broader spectrum of light, which enhances the overall efficiency of photosynthesis.

4. **Understanding the Reason (R)**:
- The reason states that these light harvesting complexes transfer electrons (e^(-)) to the reaction center.
- This transfer is essential for the conversion of light energy into chemical energy during photosynthesis.

5. **Conclusion**:
- Both the assertion and the reason are true statements.
- The reason accurately explains the assertion, as the broadening of light absorption by LHCs directly contributes to their ability to transfer electrons to the reaction center, facilitating photosynthesis.

6. **Final Answer**:
- Therefore, both the assertion (A) and the reason (R) are true, and R is the correct explanation for A. The correct option is option number one.