Answer: Failure to be specific
Explanation: Junior was trying to overcome failure to be specific language barrier, Dad was not specific about the kind of screwdriver he wanted. Language barriers are the most common communication barriers which can cause misunderstandings and misinterpretations between people, as it is seen between Dad and junior. Junior was trying to understand what the father is trying to communicate in particular hereby prompting him to ask that question (what kind) in other not to misunderstand his dad.