Assertion Green edge flame rest tells presence of borate ion.
Reason: Green colour of the flame is due to burining of tri ethyl borate.

Options

A. If assertion is true but the reason is false
B. If assertion is false but reason is true
C. If both assertion and reason are true and reason is the correct explanation of assertion
D. If oth assertion and reason are true but reason is not the correct explanation of assertion

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that a green edge flame indicates the presence of the borate ion. This is a common test used in qualitative inorganic analysis to identify borate ions.

**Hint**: Think about the significance of flame tests in identifying specific ions.

2. **Analyzing the Reason**: The reason provided is that the green color of the flame is due to the burning of triethyl borate. Triethyl borate is a compound formed when borate ions react with ethanol in the presence of concentrated sulfuric acid.

**Hint**: Consider the chemical reactions involved in the formation of triethyl borate from borate ions.

3. **Chemical Reaction**: When borate ions are treated with concentrated sulfuric acid and ethanol, triethyl borate (C2H5)3B is produced. The reaction can be summarized as follows:
\[ \text{Borate ion} + \text{Concentrated } H_2SO_4 + \text{Ethanol} \rightarrow \text{Triethyl borate} \]

**Hint**: Recall the role of concentrated sulfuric acid in facilitating the reaction.

4. **Burning of Triethyl Borate**: When triethyl borate is burned, it produces a green flame. This is a characteristic color associated with the presence of boron compounds.

**Hint**: Think about how different compounds produce different flame colors when burned.

5. **Conclusion**: Since the assertion is that a green edge flame indicates the presence of borate ions, and the reason explains that this green color is due to the burning of triethyl borate, both the assertion and the reason are correct. Furthermore, the reason provides a correct explanation for the assertion.

**Final Answer**: Therefore, both the assertion and reason are correct, and the reason is the correct explanation for the assertion.

### Final Answer: Option 3 (Both Assertion and Reason are Correct, and Reason is the Correct Explanation for Assertion)