The scientist's theory, initially dismissed as too ______, gained significant traction after new data emerged that strongly supported its unconventional premises.

✓ Correct Answer: Option B

If a theory was initially dismissed but later gained traction, it was likely considered 'untenable' (not able to be maintained or defended against attack or objection). 'Dogmatic' refers to rigid adherence to beliefs, 'immutable' to unchanging, and 'verifiable' to provable.