Concept:The urinary tubule makes a specific hairpin turn while connecting the proximal and distal convoluted tubules.Explanation:The proximal convoluted tubule continues as a straight descending limb.It then bends sharply to form a hairpin-like turn called the loop of Henle.This bend gives the structure a U-shaped appearance.The ascending limb of the loop leads into the distal convoluted tubule.Therefore, the urinary tubule coils from proximal to distal by forming a U-shaped loop.Answer:C. U-shaped loop