The duct which is labelled as 'A' is called the hepatopancreatic duct.
The secretion of bile from the liver is possible with the hepatic duct from the liver.
The concentrated bile juice contains bile pigments and bile juice is secreted from the liver and is stored in the gall bladder.
If the hepatopancreatic duct is blocked in the pancreatic juice containing the pancreatic enzymes and bile juice.
The pancreatic juice contains pancreatic amylase which facilities the digestion of carbohydrates.
The pancreatic juice contains trypsinogen which gets activated to trypsin. Trypsin is responsible for the digestion of proteins.
The pancreatic juice contains pancreatic lipase and along with it, bile pigment is responsible for the proper digestion of fats.
Digestion of all carbohydrates, proteins and fats is affected when the hepatopancreatic duct is blocked.
Hence, the correct answer is option (D).