Answer:
The correct answer is "duct".
Step-by-step explanation:
The structures at which substances are secreted in the body are known as ducts. For instance, the liver and the pancreas act as exocrine glands liberating bile and pancreatic juice, respectively. These exocrine glands secrete the substances from the gastrointestinal tract through a series of ducts. The ducts could be branched or unbranched, depending on the location at which the exocrine secretion takes place.