The reason why the Qing government's "preparatory constitutionalism" was a scam was mainly because A. delayed constitutionalism in the name of "preparation" and B. Zai Feng was the regent.

This multiple-choice question examines the ability to analyze problems and combine history with theory from the perspective of "reason". The reason why the Qing government's "preparation for constitutionalism" is a scam is mainly because the essence of "preparation for constitutionalism" is "trying to safeguard the autocratic power of monarchy". Therefore, to solve this problem, we must think about the relationship between phenomenon and essence.