Assertion : The sound which cannot be heard pleasantly is called noise.
Reason : The sound above 80 dB becomes painful.

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 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: "The sound which cannot be heard pleasantly is called noise."
- This means that any sound that is unpleasant or disturbing to hear is classified as noise.

### Step 2: Understand the Reason
The reason states: "The sound above 80 dB becomes painful."
- This indicates that sounds that exceed 80 decibels can cause discomfort or pain to human ears.

### Step 3: Evaluate the Truth of the Assertion
- The assertion is true because noise is indeed defined as unpleasant sound. Sounds that are jarring or irritating fall into this category.

### Step 4: Evaluate the Truth of the Reason
- The reason is also true. Sounds above 80 dB can be painful and are often considered harmful to hearing.

### Step 5: Determine the Relationship Between Assertion and Reason
- While both the assertion and the reason are true, the reason does not directly explain the assertion. The assertion defines noise based on pleasantness, while the reason provides a specific threshold (80 dB) that can lead to pain, but does not encompass all noise.

### Conclusion
Both the assertion and the reason are true, but the reason is not the correct explanation for the assertion. Therefore, the answer is that both are true, but the reason is not the correct explanation of the assertion.

### Final Answer
The correct option is: Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.

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