Final answer:
The synonym for 'tentative' is 'provisional', as both terms imply something temporary and subject to change.
Step-by-step explanation:
The synonym for tentative is d. Provisional. The words 'tentative' and 'provisional' both suggest something that is temporary or not yet fixed and may be subject to change. This aspect of uncertainty and lack of permanence is what connects the two terms, making 'provisional' a suitable synonym for 'tentative'. While 'hesitant' is also related, it speaks more to a behavior or attitude of uncertainty, rather than the temporary nature of a situation or agreement, making it less suitable as a synonym in this context.