Assertion: Nephrons are of two types: cortical and juxtamedullary according to their relative position in the cortex.
Reason, Juxtamedullary nephrons have short loop of Henle while cortical nephrons have long loop of Henle.

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

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that nephrons are classified into two types: cortical and juxtamedullary, based on their relative position in the kidney cortex. This is a true statement. Cortical nephrons are located in the outer cortex, while juxtamedullary nephrons are situated deeper in the cortex, near the medulla.

2. **Understanding the Reason**: The reason provided states that juxtamedullary nephrons have short loops of Henle, while cortical nephrons have long loops of Henle. This statement is incorrect. In reality, juxtamedullary nephrons have long loops of Henle that extend deep into the medulla, while cortical nephrons have shorter loops of Henle that only penetrate a short distance into the medulla.

3. **Conclusion**: Since the assertion is correct and the reason is incorrect, we can conclude that the assertion is true, but the reason is false.

### Final Answer:
- **Assertion**: True
- **Reason**: False