<s>[INST] context: ANs- B Benznidazole Ref- Treatment To kill the parasite, Chagas disease can be treated with benznidazole and also nifurtimox. Both medicines are almost 100% effective in curing the disease if given soon after infection at the onset of the acute phase including the cases of congenital transmission. The efficacy of both diminishes, however, the longer a person has been infected. Treatment is also indicated for those in whom the infection has been reactivated (for example, due to immunosuppression), and for patients during the early chronic phase. Infected adults, especially those with no symptoms, should be offered treatment because antiparasitic treatment can also prevent or curb disease progression and prevent congenital transmission in pregnant women. In those cases the potential benefits of medication in preventing or delaying the development of Chagas disease should be weighed against the long duration of treatment (up to 2 months) and possible adverse reactions (occurring in up to 40% of treated patients). Benznidazole and nifurtimox should not be taken by pregnant women or by people with kidney or liver failure. Nifurtimox is also contraindicated for people with a background of neurological or psychiatric disorders. Additionally, specific treatment for cardiac or digestive manifestations may be required. [/INST] question: Drug of choice in CHAGAS disease is - | options: A: Suramin B: Benznidazole C: Pentamidine D: Nifurtimox | answer: B </s>