What to provide the user to use a table index during request?

Question

I want to know if oracle uses an index when a user requests data from a table and this user was provided simply:
grant select on table to user

I want to know if any other grant is needed to use the index.

Answer 1

No, there is no requirement (or ability) to provide access to the index. If the user can access the table, then their queries can use any available index.