The correct option is C duodenum
Secretin and cholecystokinin (CCK) are two main gastrointestinal (GI) hormones secreted by the duodenum of alimentary canal. CCK stimulates gall bladder contraction and thus, increases the flow of bile salts into the intestine. While, secretin stimulates the release of an alkaline pancreatic fluid that neutralizes stomach acid as it enters the intestine.