Which of the following is both endocrine and exocrine gland?

A. thyroid
B. pancreas
C. parathyroid
D. all of these

The liver and pancreas are both exocrine and endocrine glands; they are exocrine glands because they secrete products—bile and pancreatic juice—into the gastrointestinal tract through a series of ducts, and endocrine because they secrete other substances directly into the bloodstream.