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 "Select the correct statement," we will analyze each statement provided in the options.

### Step-by-Step Solution:

1. **Evaluate the First Statement:**
- The first statement claims that "the inter-arterial septum is the thick partition while the atrioventricular partition is thin."
- **Analysis:** The inter-arterial septum is actually a thin partition between the two arteries, while the atrioventricular septum (or partition) is thick.
- **Conclusion:** This statement is incorrect.

2. **Evaluate the Second Statement:**
- The second statement states that "the mitral valve has two fibrous non-muscular cusps."
- **Analysis:** The mitral valve actually has two cusps that are fibrous but also muscular. Therefore, it is not accurate to say they are non-muscular.
- **Conclusion:** This statement is also incorrect.

3. **Evaluate the Third Statement:**
- The third statement mentions that "the size of the heart is equivalent to the size of the clenched fist."
- **Analysis:** This is a well-known fact; the heart is approximately the size of a person's clenched fist.
- **Conclusion:** This statement is correct.

4. **Evaluate the Fourth Statement:**
- The fourth statement claims "all of the above."
- **Analysis:** Since the first and second statements are incorrect, this option cannot be correct.
- **Conclusion:** This statement is incorrect.

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

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