Which of the following words is closest in meaning to “Sceptical”?

Sceptical means doubtful; not easily convinced.

• Correct answer - dubious: it has the same meaning as Sceptical.
• convinced: completely sure - wrong, it does not mean the same as Sceptical.
• startled: suddenly surprised - wrong, it does not mean the same as Sceptical.
• naive: innocent and inexperienced - wrong, it does not mean the same as Sceptical.