This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Mucin is not secreted by 
Select and explain. 
A. Goblet cell, B. Paneth cell, C. Brunner's gland, D. Crypts of Lieberkuhn
B: Paneth cell
Answer: B: Paneth cell 
Explanation: Paneth cells are a specific type of cell within the crypts of Lieberkuhn.
These cells have atypically oriented bright eosinophilic granules containing a variety of antimicrobial proteins and play a role in mucosal immunity (and not mucin secretion)

Brunner's glands: are sub-mucosal mucus gland within the duodenum.
Goblet cells: are mucin-secreting cells.
Crypts of Lieberkuhn: are lined by goblet cells besides other cell types.

These are thus also involved in mucin secretion.