<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 4-year-old boy is brought to the physician because of a rash and difficulty swallowing. His family emigrated from Nigeria 2 months ago. Examination shows an erythematous rash with fine yellow scales on his eyebrows and nasolabial folds. Oral examination shows an erythematous throat and swollen tongue. There is peeling and fissures of the skin at the corners of the mouth and cracking of the lips. His hemoglobin concentration is 9.6 gdL; mean corpuscular volume is 89 μm3. Erythrocyte glutathione reductase assay shows an increased activity coefficient. This patient is most likely deficient in a vitamin that is a precursor to which of the following molecules?? A: Thiamine pyrophosphate, B: Flavin adenine dinucleotide, C: Nicotinamide adenine dinucleotide, D: Methylcobalamin, E: Pyridoxal phosphate,  <response>: This is a question about nutritional deficiency in a child who recently immigrated from Nigeria. The symptoms described include rash, difficulty swallowing, erythematous throat, swollen tongue, mouth sores, anemia, and increased erythrocyte glutathione reductase assay. These symptoms are classic for riboflavin vitamin B2 deficiency. Riboflavin is a precursor to flavin adenine dinucleotide FAD, an important cofactor in many enzymatic reactions. The increased erythrocyte glutathione reductase assay specifically indicates riboflavin deficiency, as glutathione reductase requires FAD as a cofactor.B: Flavin adenine dinucleotide 