Assertion : London smog is oxidising in nature .
Reason : London somg contains `O_(3), NO_(2)` and Hydrocabons .

Options

A. Both assertion and reason are true and Reason is the correct explanation of Assertion
B. Both assertion and reason are true but Reason is notcorrect explanation of Assertion
C. Assertion is ture but Reason is false
D. Assertion is false but Reason is true

Answer

To analyze the assertion and reason provided in the question, we need to evaluate both statements carefully.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "London smog is oxidizing in nature."
- To evaluate this, we need to consider the composition of London smog and its effects. Historically, London smog, particularly the infamous Great Smog of 1952, was primarily composed of sulfur dioxide (SO2) and particulate matter from coal combustion. This type of smog is known for its reducing properties due to the presence of SO2.

2. **Understanding the Reason**:
- The reason states that "London smog contains O3 (ozone), NO2 (nitrogen dioxide), and hydrocarbons."
- While ozone (O3) and nitrogen dioxide (NO2) are indeed oxidizing agents, they were not the primary constituents of the London smog that is being referred to in the assertion. The dominant component was sulfur dioxide, which contributes to a reducing atmosphere.

3. **Evaluating the Truth of Each Statement**:
- Since London smog is primarily a reducing mixture due to high concentrations of sulfur dioxide, the assertion that it is oxidizing in nature is **false**.
- The reason provided mentions components that are generally oxidizing; however, during the historical context of London smog, these were not the main contributors. Therefore, the reason is also **false**.

4. **Conclusion**:
- Both the assertion and the reason are false. Thus, the correct answer to the question is that both statements do not hold true.

### Final Answer:
Both the assertion and reason are false.

---