Assertion : Chlorine sinks are formed during summer, hence , preventing ozone depletion.
Reason : In summer seasons, nitrogen dioxide and methane react with chlorine monoxide and chlorine radicals.

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 c orrect explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

To analyze the given assertion and reason, we will break down the information step by step.

### Step 1: Understanding the Assertion
The assertion states that "Chlorine sinks are formed during summer, hence preventing ozone depletion."
- Chlorine sinks are processes or reactions that effectively remove chlorine from the atmosphere, thus preventing it from contributing to ozone layer depletion.

### Step 2: Understanding the Reason
The reason provided is "In summer seasons, nitrogen dioxide and methane react with chlorine monoxide and chlorine radicals."
- This implies that during summer, certain reactions occur that involve chlorine compounds and other atmospheric gases, leading to the formation of chlorine sinks.

### Step 3: Analyzing the Reactions
1. **Chlorine Monoxide Reaction**:
- Chlorine monoxide (ClO) reacts with nitrogen dioxide (NO2) to form ClONO2 (chlorine nitrate).
- Reaction:
\[ \text{ClO} + \text{NO}_2 \rightarrow \text{ClONO}_2 \]

2. **Methane Reaction**:
- Chlorine gas (Cl2) reacts with methane (CH4) to produce methyl radical (CH3) and hydrochloric acid (HCl).
- Reaction:
\[ \text{Cl}_2 + \text{CH}_4 \rightarrow \text{CH}_3 + \text{HCl} \]

3. **Formation of HOCl and HNO3**:
- ClONO2 can react with water (H2O) to form hypochlorous acid (HOCl) and nitric acid (HNO3).
- Reaction:
\[ \text{ClONO}_2 + \text{H}_2\text{O} \rightarrow \text{HOCl} + \text{HNO}_3 \]

### Step 4: Role of Sunlight
- When sunlight returns in the spring, it breaks down the chlorine compounds (like HOCl and Cl2) into chlorine radicals.
- This photolysis process leads to the release of chlorine radicals, which can then contribute to ozone depletion.

### Step 5: Conclusion
- Both the assertion and reason are correct. The formation of chlorine sinks during summer does help in preventing ozone depletion, and the reactions involving chlorine monoxide, nitrogen dioxide, and methane are crucial in this process. Therefore, the reason is a correct explanation of the assertion.

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

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