( A ) Nearly all of the essential nutrients, and 70-80 per cent of electrolytes and water are reabsorbed by this segment.
( B ) PCT is lined by simple cuboidal brush border epithelium which increases the surface area for reabsorption.
( C ) PCT also helps to maintain the pH and ionic balance of the body fluids by selective secretion of hydrogen ions, ammonia and potassium ions into the filtrate and by absorption of HCO3– from it.
( D ) none of the above
