This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Medicine
1772. A patient presents with macroglossla and loss of tongue papilla. His Hb Is 11.5 and MCV Is 100. What shuld be the next step In investigating this patient ? 
Select and explain. 
A. B12 estimation, B. Brush biopsy of the lesion, C. Fluconazole treatment, D. Incision biopsy
A: B12 estimation
Answer: A: B12 estimation 
Explanation: Question repeated .