Assertion : Splitting of the spectral lines in the presence of magnetic field is known as stark effect.
Reason : Line spectrum is simplest for hydrogen atom.

Options

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

Explanation

To solve the question, we need to analyze both the assertion and the reason provided:

### Step 1: Understand the Assertion
The assertion states: "Splitting of the spectral lines in the presence of magnetic field is known as Stark effect."

- The Stark effect refers to the splitting of spectral lines when an electric field is applied, not a magnetic field. Therefore, this assertion is incorrect.

### Step 2: Understand the Reason
The reason states: "Line spectrum is simplest for hydrogen atom."

- The line spectrum of hydrogen is indeed the simplest among all elements because hydrogen has only one electron. This makes its spectral lines easier to analyze and understand. Therefore, this reason is correct.

### Step 3: Conclusion
Based on the analysis:
- The assertion is false because it incorrectly identifies the Stark effect as the phenomenon related to magnetic fields.
- The reason is true because the hydrogen atom has the simplest line spectrum.

Thus, the correct answer is that the assertion is false, but the reason is true.

### Final Answer:
Assertion is false, Reason is true.

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