<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 19-year-old woman with a known history of malabsorption presents with a painful red tongue, red eyes, and cracked lips. She says her symptoms gradually onset 4 months ago after moving away from home for college. She also complains of photophobia, spontaneous lacrimation, and itchy dermatitis. Past medical history is significant for a long-standing malabsorption syndrome, which she says that she hasnt been able to maintain her normal diet or take her vitamins regularly due to her busy schedule. The patient is afebrile and vital signs are within normal limits. On physical examination, she has a malnourished appearance with significant pallor. Conjunctival injection is present bilaterally. Which of the following diagnostic tests will be most helpful to support the diagnosis of the most likely vitamin deficiency in this patient?? A: Measurement of erythrocyte glutamic oxaloacetic transaminase activity, B: Measurement of serum methylmalonic acid levels, C: Measurement of erythrocyte folate levels, D: Measurement of erythrocyte glutathione reductase activity, E: Measurement of erythrocyte transketolase activity,  <response>: Based on the patients history of malabsorption and inability to maintain her normal diet or take vitamins regularly, she likely has a vitamin deficiency. The symptoms of red tongue, red eyes, cracked lips, photophobia, tearing, and itchy dermatitis point towards a deficiency in one of the B vitamins. The two main possibilities are vitamin B2 riboflavin deficiency or vitamin B6 pyridoxine deficiency. Measurement of erythrocyte glutathione reductase activity would help determine if she has a riboflavin deficiency, as this enzyme requires riboflavin as a cofactor. Measurement of erythrocyte transketolase activity would help determine if she has a thiamine vitamin B1 deficiency. The other tests listed would not be as helpful in diagnosing the most likely vitamin deficiency in this patient.D: Measurement of erythrocyte glutathione reductase activity 