Step 1: Understanding the Concept
Nephritis is inflammation of the kidneys, mainly of the glomeruli (glomerulonephritis).
Step 2: Associated features
The damaged filtration membrane lets plasma proteins pass into urine, causing proteinuria. Loss of proteins changes the blood colloidal osmotic pressure and may cause oedema.
Step 3: Odd one out
Obstruction of both ureters is a blockage of urine outflow, for example by stones. It causes back pressure and urine retention, not inflammation of the kidney.
Final Answer:
Obstruction of both ureters is not associated with nephritis.
\[ \boxed{\text{(B) }\text{Obstruction of both the ureters.}} \]