A 34-year-old female presents to her physician complaining of oral ulcers. A careful history reveals that she is a strict vegetarian and does not eat meat, fish, poultry, eggs, or dairy products. She is found to have a severe riboflavin deficiency. The function of which of the following enzymes in the citric acid cycle would be most directly affected by the riboflavin deficiency?

1. A)Citrate synthase
2. B)Malate dehydrogenase
3. C)Isocitrate dehydrogenase
4. D)Succinate dehydrogenaseGABARITO
5. E)Aconitase