[A]: Person having increased blood urea level suffers from kidney disease.
[R]: Urea cycle operates in kidney.

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

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that a person with an increased blood urea level suffers from kidney disease. This is a true statement because elevated blood urea levels indicate that the kidneys are not functioning properly, leading to a condition known as uremia.

2. **Understanding the Reason**: The reason given is that the urea cycle operates in the kidney. This statement is false. The urea cycle primarily occurs in the liver, where ammonia is converted into urea, which is then transported to the kidneys for excretion.

3. **Evaluating the Relationship**: We need to determine if the reason explains the assertion. Since the assertion is true (increased blood urea indicates kidney disease) and the reason is false (urea cycle does not operate in the kidney), the reason does not provide a correct explanation for the assertion.

4. **Selecting the Correct Option**: Based on the evaluation:
- Assertion (A) is true.
- Reason (R) is false.
Therefore, the correct option is C, which states that A is true and R is false.

### Final Answer:
The correct option is C: A is true and R is false.

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