Any organization must consider changing its basic structure if there is a dramatic change in its size. Doubling or tripling in size can lead to inefficiency and mismanagement, which restructuring often alleviates. Experience further shows that the more dramatic the change in size, the more fundamental the restructuring needs to be. Ttherefore, any organization must consider changing its basic structure once it is 20 years old. The argument's conclusion follows logically if which one of the following is assumed? ['No organization that has not been restructured is as efficient as any organization that has been restructured.', 'Any organization that has existed for 20 years has undergone a dramatic change in size.', 'No organization that has remained the same size for 20 years is efficient.', 'No organization that has not changed in size needs restructuring.']