Option 1 -> To prove something wrong or false through evidence; fits the contrast between the theory seeming plausible and experimental evidence disproving it.
Option 2 -> Means covered with a hard coating; makes no sense in the context of a theory and experimental evidence.
Option 3 -> Means controlled by rules; doesn't capture the contrast implied by "although" and doesn't fit with experimental evidence.
Option 4 -> Means renovated or restored; inappropriate for describing what happens to a theory based on experimental evidence.
Hence, Option 1: refuted -> The word "although" signals a contrast—while the theory initially seemed reasonable, experimental evidence ultimately proved it false. "Refuted" perfectly captures this relationship between a theory and contradictory evidence. -> correct