(A) At the eleventh hour → (III) work at the last minute - This idiom refers to doing something at the very last moment before a deadline.
(B) To burn one's boats → (IV) point of no return - This means to commit to a course of action so completely that you cannot retreat or change your mind.
(C) To curry favours → (I) to ingratiate oneself with someone by obedient behaviour - This means to seek someone's approval through flattery or servile behavior.
(D) Chip in → (II) contribute one's share in a joint activity - This means to contribute money, effort, or ideas to a common cause.
Hence, Option 4: (A) - (III), (B) - (IV), (C) - (I), (D) - (II) → All four idioms are correctly matched with their precise meanings, demonstrating accurate understanding of common English expressions → correct