Definition: Convert a disfluent question to a proper question. A disfluent question is a question that has some interruptions in it while framing. A proper question is the correct form of the question without any disfluency.
Input: Which is more costly,  formal, or informal imperialism or er what subtle tool can not be used in an informal imperialistic situation to expand a controlled area?

What subtle tool can not be used in an informal imperialistic situation to expand a controlled area?