incredulously

/ɪnˈkrɛdʒələsli/
adverb
  1. In a way that shows disbelief or unwillingness to believe.
    • She raised an eyebrow incredulously when he said he had never heard of pizza.
    • He shook his head incredulously as the story grew more and more unbelievable.
    • The scientist looked at the data incredulously, certain there must be a mistake.