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: Surgery
Cause for nipple retraction in breast carcinoma is 
Select and explain. 
A. Blocking of lymphatics, B. Involvement of the Cooper's ligament, C. Infiltration of ducts, D. Skin infiltration
C: Infiltration of ducts
Answer: C: Infiltration of ducts 
Explanation: Infiltration of the Cooper’s ligament will give rise to dimpling of skin.
Blocking of subcutaneous lymph nodes will give rise to peau d'orange appearance.