Explanation:

- The sentence talks about someone having the audacity to blame another person.

- Audacity typically means a bold or daring quality, often without regard for conventional thought.

- Option 1, boldness, shares a similar meaning. It's about confidence or courage in doing something.

- Option 2, vigour, is about energy or enthusiasm, which doesn't directly relate to boldness.

- Option 3, temerity, also means excessive confidence or rash boldness, similar to audacity.

- Option 4, politeness, is about showing good manners and being respectful, which is opposite to being bold or audacious.

The correct antonym for audacity in this context is politeness.

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