Alkaline medium is essential for the functioning of pancreatic juice, which is provided by
Pancreatic juice is a liquid secreted by the pancreas, which contains a variety of enzymes, including trypsinogen, chymotrypsinogen, elastase, carboxypeptidase, pancreatic lipase, nucleases and amylase.
This pancreatic juice is alkaline in nature due to the high concentration of bicarbonate ions. Bicarbonate ions are useful in neutralizing the acidic gastric acid, allowing for effective enzyme changes. Hence, the alkaline medium is essential for the functioning of pancreatic juice, which is provided by The secretion of bicarbonate from the pancreas.
So, the correct option is 'The secretion of bicarbonate from the pancreas'.