What term describes a state of uncertainty or suspicion regarding something?

The term that describes a state of uncertainty or suspicion is "doubtful." This word encapsulates feelings of doubt, skepticism, and lack of confidence in something. When someone is doubtful, they have reservations or concerns about the reliability, truth, or validity of a situation or information.

In this context, the term reflects an emotional or cognitive response to information that does not feel completely trustworthy or clear. In contrast, the other terms such as "obvious," "sure," and "certain" denote a sense of clarity, assurance, or confidence, which directly opposes the idea of uncertainty or suspicion. Therefore, "doubtful" is the most fitting term to describe that particular state of mind.