Assertion : Closed circulatory system is less efficient than open circulatory system
Reason : The blood flow is slow is closed circulatory system than in open circulatory system.

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 regarding the assertion and reason about the circulatory systems, we will analyze both statements step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Closed circulatory system is less efficient than open circulatory system."
- In reality, closed circulatory systems (like those found in vertebrates) are generally more efficient than open circulatory systems (like those found in arthropods). This is because closed systems allow for more controlled and faster blood flow, which can deliver oxygen and nutrients more effectively to tissues.

2. **Understanding the Reason**:
- The reason provided is "The blood flow is slow in closed circulatory system than in open circulatory system."
- This statement is also incorrect. In closed circulatory systems, blood flow is typically faster due to the presence of blood vessels that create a more direct route for blood circulation. The pressure generated by the heart in a closed system allows for quicker transport of blood compared to the slower, less directed flow in an open system.

3. **Conclusion**:
- Since both the assertion and the reason are incorrect, we conclude that the correct answer is that both the assertion and reason are false.

### Final Answer:
Both the assertion and reason are false.

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