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: Medicine
All are TRUE about foregut carcinoid tumors, EXCEPT: 
Select and explain. 
A. Foregut tumors generally have a low serotonin content, B. Argentaffin-negative but argyrophilic, C. Often multi hormonal, D. Bone metastasis in not a feature
D: Bone metastasis in not a feature
Answer: D: Bone metastasis in not a feature 
Explanation: Foregut carcinoid tumors generally have a low serotonin content. They are argentaffin-negative but argyrophilic and occasionally secrete adrenocoicotropic hormone or 5-hydroxytryptophan, causing an atypical carcinoid syndrome. They are often multi hormonal and metastasize to bone. Ref: Harrisons Principles of Internal Medicine, 18th Edition, Page 3058.