You are answering a USMLE-style medical question. Question: A 42-year-old man is admitted to the intensive care unit with decreased consciousness and convulsions. His wife reports that 30 min following the onset of her husband’s condition, which started approximately 6 hours ago, he treated his garden bed with pesticides against mice. He developed nausea, vomiting, and abdominal cramps. The patient noted facial muscle twitching and developed a tonic-clonic seizure that lasted 3 minutes, 4 hours following the onset of his condition. His past medical history is insignificant for any seizure disorders, and he does not take any medications. His blood pressure is 95/60 mm Hg, heart rate is 104/min, respiratory rate is 10/min, and the temperature is 37.0°C (98.6°F). On physical examination, the patient’s consciousness is decreased with a Glasgow Coma Scale score of 13. He is pale and sweaty. His lung sounds are normal, cardiac sounds are decreased, and no murmurs are present. Abdominal palpation reveals epigastric tenderness. Neurological examination shows rapid downbeating nystagmus, facial muscle twitching, and symmetrically decreased sensation to all the sensory modalities on both the upper and lower extremities. Further discussion reveals that the patient was using sodium fluoroacetate as a pesticide, which is known to form fluorocitrate in the cells of aerobic organisms. Which of the following substances will accumulate in the patient’s cells? Options: A) Fumarate B) Citrate C) Malate D) Succinate Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.