[A] : Mammals lack mucous glands in their skin.
[R] : The epidermis has many layers of cells.

Options

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

Answer

To analyze the assertion and reason provided in the question, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Mammals lack mucous glands in their skin."
- This is true because mammals do not have mucous glands in their skin. Instead, these glands are located internally in various organs such as the windpipe, nasal chambers, and alimentary canal.

2. **Understanding the Reason**:
- The reason states that "The epidermis has many layers of cells."
- This statement is also true. The epidermis, which is the outermost layer of the skin, consists of multiple layers of cells (typically 4 to 5 layers depending on the region).

3. **Evaluating the Relationship**:
- While both the assertion and the reason are true, they are independent statements. The presence of multiple layers in the epidermis does not explain why mucous glands are absent in the skin of mammals. The absence of mucous glands is related to the fact that mammals do not respire through their skin but rather through specialized organs like lungs.

4. **Conclusion**:
- Since both statements are true but the reason does not correctly explain the assertion, the correct answer is: "Both assertion and reason are true, but the reason is not the correct explanation for the assertion."

### Final Answer:
- The correct option is: **Both assertion and reason true; reason is not the correct explanation.**

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