This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology and breast, Subject name: Surgery
Best definitive investigation for carcinoma breast is ? 
Select and explain. 
A. Biopsy, B. FNAC, C. USG, D. Mammography
A: Biopsy
Answer: A: Biopsy 
Explanation: .* Corecut/Trucut biopsy is done under local anaesthesia. It gives clear histological evidence and also confirms DCIS (FNAC can not confirm DCIS). This allows proper neoadjuvant/primary chemotherapy, receptor status of the tumour. Wide bore needle biopsy with vacuum is also used. * Excision biopsy is done only when FNAC is inconclusive and a facility for frozen section is not available. Incision should be planned in such a way that it will be included in eventual mastectomy. ref:SRB&;s manual of surgery,ed 3,pg no 478