A 47-year-old man presents with progressive chorea, irritability, and impulsive aggression affecting work performance. Vital signs: BP 128/82, HR 92, RR 16, Temp 37°C, SpO2 98%. MRI shows mild caudate atrophy. He denies depression or suicidality. Genetic testing confirms expanded CAG repeat in the HTT gene. Which neurotransmitter change is most likely present in the affected striatum early in this disease?

1. A)Increased dopamine and decreased GABA in the striatumGABARITO
2. B)Decreased glutamate and increased GABA in the cerebellum
3. C)Decreased dopamine and increased acetylcholine in the substantia nigra
4. D)Increased acetylcholine and decreased dopamine in the hippocampus
5. E)Increased serotonin and decreased norepinephrine in the locus coeruleus