Choose the correct meaning of the following idiom:

At arm's length

At a distance

The correct meaning of the idiom "at arm's length" is at a distance. It means that someone or something is kept at a distance, either physically or emotionally. The idiom is thought to have originated from the fact that the length of an arm is a convenient way to measure distance.

The other options are incorrect. "Length of arm" is the actual length of an arm. "Insult" is a rude or offensive remark. "Very near" means close by.