Assertion : The threshold frequency of photoelectric effect supports the particle nature of light.
Reason : If frequency of incident light is less than the threshold frequency, electrons are not emitted from metal surface.

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

To solve the question, we will analyze both the assertion and the reason provided, and then determine their validity and relationship.

### Step 1: Understand the Assertion
The assertion states that "The threshold frequency of the photoelectric effect supports the particle nature of light."

- **Explanation**: The threshold frequency is the minimum frequency of incident light required to emit electrons from a metal surface. This concept supports the particle nature of light because it implies that light is made of discrete packets of energy called photons. Each photon must have a certain minimum energy (related to the threshold frequency) to release an electron.

### Step 2: Understand the Reason
The reason states that "If the frequency of incident light is less than the threshold frequency, electrons are not emitted from the metal surface."

- **Explanation**: This statement is true. If the frequency of the incident light is below the threshold frequency, the energy of the photons is insufficient to overcome the work function of the metal, and thus no electrons are emitted. This observation is consistent with the particle model, where each photon must have enough energy to cause the emission of an electron.

### Step 3: Analyze the Relationship
Now, we need to determine if the reason is a correct explanation of the assertion.

- **Assertion Validity**: The assertion is correct because the threshold frequency indeed supports the particle nature of light.
- **Reason Validity**: The reason is also correct as it accurately describes the condition under which electrons are emitted.
- **Explanation Validity**: However, while both statements are correct, the reason does not explain why the threshold frequency supports the particle nature of light. It simply states a condition for electron emission without linking it back to the particle nature of light.

### Conclusion
Both the assertion and the reason are correct, but the reason is not the correct explanation for the assertion.

### Final Answer
Both the assertion and reason are correct, but the reason is not the correct explanation of the assertion.

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