Generally, the hormones secretin and cholecystokinin which are released by duodenal enteroendocrine cells will

Slows the stomach activity.

Explanation:

Digestion may be defined as the process of breakdown of large food particles into smaller substance with the help of digestive enzymes and juices.

Secretin regulates the water homeostasis in the body. Cholecystokinin regulates the bile activity and stimulate pancreas juices secretion. Secretin and cholecystokinin release together in the small intestine and inhibits the stomach activity. These hormone causes satiety to the hypothalamus, slows the stomach activity.

this is true, assuming that the allele is completely recessive and incomplete dominance is not a factor.