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: Radiology
Investigation to diagnose stage-I carcinoma breast: 
Select and explain. 
A. B/ L mammogram, B. X-ray chest, C. Bone scan, D. Liver scan
A: B/ L mammogram
Answer: A: B/ L mammogram 
Explanation: A i.e. B/L mammogram