Explain How the Secretion of Cholecystokinin in Response to Fats

Explain how the secretion of cholecystokinin in response to fats in the duodenum,together with the actions of cholecystokinin,constitute a negative feedback mechanism.

A) Contraction of the gall bladder moves bile into the duodenum.
B) Pancreatic enzymes include lipase,which digests fat.
C) Bile contains bile salts,which emulsify fats.
D) As fats are digested,the stimulus for secretion of further cholecystokinin is removed.
E) All of these are necessary components of this negative feedback mechanism.