A 50-year-old male with a 20-year history of alcohol use disorder presents with confusion, ophthalmoplegia affecting lateral gaze, and ataxia. Vital signs show BP 128/76 mmHg, HR 92 bpm, RR 16/min, temperature 37.2°C, and SpO2 98% on room air. MRI demonstrates mammillary body atrophy. Serum thiamine level is low at 2.5 ng/mL (normal >5.5). He denies recent seizures. Which enzyme requires the deficient vitamin as a cofactor?

1. A)Aspartate aminotransferase
2. B)Pyruvate carboxylase
3. C)Methylmalonyl-CoA mutase
4. D)Prolyl hydroxylase
5. E)Pyruvate dehydrogenaseGABARITO