Option 1: Scoff -> means to mock or show contempt, similar to flout, not opposite.
Option 2: Approve -> means to accept or regard favorably, which is the opposite of openly disregarding.
Option 3: Jeer -> means to make mocking remarks, similar in sentiment to flout.
Option 4: Reject -> means to refuse or dismiss, which shares the negative sentiment of flout.
Hence, Option 2: Approve -> "Flout" means to openly disregard or disobey rules/conventions, while "approve" means to officially accept or respect something, making them antonyms -> correct