Here's a breakdown:
* Confusion: Montag is initially taken aback by the question. It's a concept he's never considered before, and it challenges his deeply ingrained beliefs about his job.
* Defensiveness: He immediately responds with a curt "No," trying to dismiss the question and its implications. He feels the need to defend his actions and the status quo.
* Unease: Beneath the surface, though, there's a sense of unease. Clarisse's question plants a seed of doubt in Montag's mind. He begins to question the emptiness of his life and the mindless routine he's accustomed to. This unease sets the stage for his later questioning and rebellion.
The question is a turning point in the novel, marking the beginning of Montag's journey of self-discovery and rebellion against the oppressive society he lives in.