Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R:Assertion A: Nephrons are of two types: Cortical & Juxta medullary, based on their relative position in cortex and medulla.Reason R: Juxta medullary nephrons have short loop of Henle whereas, cortical nephrons have longer loop of Henle.In the light of the above statements, choose the correct answer:

1. A
   Both A and R are true and R is the correct explanation of A
2. B
   Both A and R are true but R is NOT the correct explanation of A
3. C
   A is true but R is not false
4. D
   A is not false but R is true