This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Breast Cancer - Treatments, Subject name: Surgery
Sentinel lymph node biopsy in carcinoma breast is done if - 
Select and explain. 
A. LN palpable, B. Breast mass but no lymph node palpable, C. Breast lump with palpable axillary node, D. Metastatic CA breast
B: Breast mass but no lymph node palpable
Answer: B: Breast mass but no lymph node palpable 
Explanation: Ans. is 'b' i.e., Breast mass but no lymph node palpable