The correct option is A Nephron
Renal tubule is attached to each Bowman's capsule with three distinct regions proximal convoluted tubule, the loop of Henle and distal convoluted tubule. The first region is called the proximal convoluted tubule. The proximal convoluted tubule is connected to the second region, the loop of Henle. The loop of Henle has a descending limb and an ascending limb. The third region of the nephron tubule is called the distal convoluted tubule.