Explanation:

- The word "audacity" generally means boldness or daring, often in a disrespectful or rude manner.

- Option 1: Cowardice - This means lack of bravery. It is the opposite of audacity.

- Option 2: Insolence - This refers to rude and disrespectful behavior, closely related to audacity as both indicate a bold disrespect.

- Option 3: Presumption - This involves taking liberties or making assumptions without right, which can overlap with audacity in terms of taking bold actions.

- Option 4: Brevity - This means shortness in duration. It is unrelated to audacity.

- Option 5: Heed - This means careful attention, the opposite characteristic of someone who acts with audacity.

The best alternative for "audacity" is:

- Option 2: Insolence

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