Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
| Column$-I$ | Column$-II$ |
| $a.$ Capillaries | $(i)$ Valves |
| $b.$ Veins | $(ii)$ Smooth muscles |
| $c.$ Aorta | $(iii)$ Narrowest blood vessels |
| $d.$ Tunica media | $(iv)$ Elastic artery |
Select the alternative which shows the correct matching.
Assertion $A$: Nephrons are of two types: Cortical and 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 from the options given below: