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: Biochemistry
A lady presented with fatigue and tingling sensation in both hands and legs. On examination, she is found to have a fissured red tongue, lesions at angle of mouth and peripheral neuropathy with a decreased RBC glutathione reductase activity. What is the likely deficient vitamin? 
Select and explain. 
A. Riboflavin, B. Vitamin B12, C. Thiamine, D. Vitamin B6
A: Riboflavin
Answer: A: Riboflavin 
Explanation: Answer- A. RiboflavinClinical Manifestations of Riboflavin deficiency:Cheilosis, glossitis, lingual desquamation seborrheic dermatitisKeratitis, conjunctivitis, corneal vascularisation