"The politician's lies were finally exposed, and he had to ___________."

The idiom "faced the music" means to accept responsibility for one's actions, especially when it results in negative consequences. In this case, the speaker is admitting to making a mistake and taking responsibility for it. The other options are unrelated idioms. a) Pay the piper - Face the consequences of one's actions, especially when it involves a cost or a debt. b) Face the music - Accept responsibility for something, especially when it results in negative consequences. c) Kick the bucket - Euphemism for dying or passing away. d) Let the cat out of the bag - Accidentally reveal a secret or confidential information. e) Beat around the bush - Avoid talking about something directly, often by using indirect or vague language.