Select the correct statement.

Options

A. Inter - atrial septum is a thick partition while atrio - ventricular partitions are thin.
B. Mitral valve is having 2 fibrous non - muscular cusps.
C. Size of heart is equivalent to the size of clenched fist.
D. All of the above

Answer

To solve the question, we need to analyze each statement provided in the options and determine which one is correct.

### Step-by-Step Solution:

1. **Analyze the First Statement:**
- Statement: "Interarterial septum is a thick partition while atrioventricular partitions are thin."
- Explanation: The interatrial septum (not interarterial) is actually a thin partition that separates the left and right atria. In contrast, the atrioventricular septum (which includes the structures separating the atria from the ventricles) is thicker.
- Conclusion: This statement is **incorrect**.

2. **Analyze the Second Statement:**
- Statement: "Mitral valve is having two fibrous non-muscular cusps."
- Explanation: The mitral valve, also known as the bicuspid valve, does indeed have two cusps, but these cusps are fibrous and muscular, not non-muscular.
- Conclusion: This statement is **incorrect**.

3. **Analyze the Third Statement:**
- Statement: "Size of heart is equivalent to the size of clenched fist."
- Explanation: It is a common anatomical reference that the size of an adult human heart is approximately the size of a clenched fist. This is a widely accepted fact in anatomy.
- Conclusion: This statement is **correct**.

4. **Analyze the Fourth Statement:**
- Statement: "All of the above."
- Explanation: Since the first two statements are incorrect and only the third statement is correct, this option cannot be correct.
- Conclusion: This statement is **incorrect**.

### Final Answer:
The correct statement is: **"Size of heart is equivalent to the size of clenched fist."**

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