(i) If both Assertion and Reason are true: Reason is the correct explanation of Assertion.
(ii)If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
(iii) If Assertion is true but Reason is false.
(iv) If Assertion is false but Reason is true.
Assertion (A): Human lungs have enormous surface area for exchange of gases.
Reason (R): In humans, glottis is guarded by epiglottis.

Options

A. (i)
B. (ii)
C. (iii)
D. both (i) and (ii)

Answer

To solve the question regarding the Assertion (A) and Reason (R), we will analyze both statements and determine their truthfulness and relationship.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states: "Human lungs have enormous surface area for exchange of gases."
- This statement is true because human lungs contain millions of tiny air sacs called alveoli, which significantly increase the surface area available for gas exchange.

2. **Understanding the Reason (R)**:
- The reason states: "In humans, glottis is guarded by epiglottis."
- This statement is also true. The glottis is the opening of the vocal cords, and it is indeed guarded by the epiglottis, which prevents food from entering the trachea during swallowing.

3. **Analyzing the Relationship**:
- While both the assertion and reason are true, we need to determine if the reason provides a correct explanation for the assertion.
- The assertion about the surface area of the lungs relates to gas exchange, while the reason about the glottis and epiglottis pertains to the protection of the airway during swallowing. These two statements do not explain each other.

4. **Conclusion**:
- Since both the assertion and reason are true, but the reason does not explain the assertion, the correct option is:
- (ii) If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.

### Final Answer:
The answer is option (ii).

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