Final answer:
The 9-letter word that means unsure or hesitant is 'uncertain'. Despite similar meanings, alternatives like 'tentative' or 'indecisive' are either not the correct length or do not fit as well as 'uncertain'.
Step-by-step explanation:
The 9-letter word that means unsure or hesitant is uncertain. Option 'c' is correct. Neither 'tentative' (9 letters but means provisional, done without confidence), 'doubtful', nor 'indecisive' (though close in meaning, they are not 9 letters in length) fits the description as well as 'uncertain'. Additionally, 'uncertain' is precisely nine letters, aligning with the specifics of the question. It's important to recognize that the length of the word is a crucial part of the question, as illustrated by the fact that other relevant words like 'tentative' and 'indecisive' might convey similar meanings but are not the same number of letters as requested.