Gastrin-
1)acts on gastric glands
2)Stimulates secretion of HCl & pepsinogen
Secretin-
1) acts on exocrine pancreas
2) Stimulates secretion of water and bicarbonate ions
CCK (Cholecystokinin)-
1) acts on both pancreas and gall bladder
2) Stimulates the secretion of pancreatic enzymes including insulin and bile juice resp.
Gastric inhibitory peptide (GIP) -
inhibit gastric secretion and motility.
therefore correct answer is (b) i.e Cholecystokinin ( CCK)