Multiple choice general knowledge Once you suspect a person of double dealing, you ought to keep him at arm's ...... distance length aim widht Reveal answer Fill a bubble to check yourself B Correct answer Explanation The complete idiom is 'keep someone at arm's length,' meaning to maintain distance or be wary of someone due to distrust. This matches the context of suspected double-dealing where caution is appropriate. 'Arm's distance' is not the correct idiom.