What is the most appropriate meaning of the idiom?

To show a clean pair of heel

The correct answer is “To run away quickly and without looking back”.

Key Points

• The idiom "to show a clean pair of heel" means to run away quickly and without looking back. 
• It is often used to describe someone who is trying to escape from danger or trouble.
• The phrase "a clean pair of heel" refers to the fact that someone who is running away will often show the soles of their shoes as they run.
• This idiom is often used in a humorous way to describe someone who is trying to avoid a difficult situation.

Hence, the correct answer is 'Option 1'.