Assertion. Kidneys are retroperitoneal organs.
Reason. Peritoneum covers the kidneys on all sides.

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 but R is false.
D. If both A and R are false.

Answer

**Step-by-Step Solution:**

1. **Understanding the Assertion**: The assertion states that "Kidneys are retroperitoneal organs."
- Retroperitoneal means that the organs are located behind the peritoneum, which is the lining of the abdominal cavity.
- The kidneys are indeed classified as retroperitoneal organs because they are located at the back of the abdominal cavity, outside the peritoneal cavity.

2. **Understanding the Reason**: The reason states that "Peritoneum covers the kidneys on all sides."
- The peritoneum is a serous membrane that lines the abdominal cavity and covers most of the abdominal organs.
- However, the kidneys are only partially covered by the peritoneum; they are covered on the anterior (ventral) side but not on the posterior (dorsal) side.

3. **Evaluating the Statements**:
- The assertion is true because kidneys are indeed retroperitoneal organs.
- The reason is false because the peritoneum does not cover the kidneys on all sides; it only covers the anterior side.

4. **Conclusion**: Since the assertion is true and the reason is false, the correct answer is that the assertion is true but the reason is false.

**Final Answer**: A is true but R is false.

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